ADVANTAGES OF DIESEL TECHNOLOGY IN LIGHT-DUTY AUTOMOTIVE APPLICATIONS
LOREN C. MARZ - Board Certified Meteorologist (CCM #591)
Efficiency is the one thing that typically is associated with diesel engine technology. The following are reference citations which compare its efficiency relative to other automotive technology.
"...the ranking between drive systems is (with one exception) the same independent of motor fuel type, namely:
-hybrid with diesel-engine
-hybrid with fuel cell
-direct operation with fuel cell
-hybrid with otto-engine
-(hybrid with direct-methanol fuel cell)
(The exception is the hybrid with otto-engine, which with for this engine particularly suitable fuels has higher efficiency than for system with direct fuel cell operation.)..."
"...The fuel cell is the fuel converter that has the highest efficiency and in combination with a hybrid drivetrain, it has the highest efficiency of all powertrains. Of the fuel converters, the diesel engine has the second highest efficiency and the otto engine has the lowest efficiency. It is also notable that the difference in efficiency between the best piston engine (diesel hybrid) and the fuel cell hybrid is not remarkably great (21,2% vs. 23,5%). The relative difference is not more than about 10%. This might seem controversial but it appears to be in line with the findings from the PNGV programme as shown above (Figure 5). The improvement potential by a factor as high as 2 to 3, which is often cited for fuel cells powertrains, seems very unlikely in view of our results and the results from the PNGV programme...."
"...As a summary of the results from this study, it can be stated that it is not trivial to find a final "winner" among the 3 to 5 best candidate fuels. On the contrary, it is easier to exclude some of the options where the system efficiency is comparatively low. Hydrogen produced from electricity is such a case."
"Hydrogen produced from electricity appears to be the least efficient fuel pathway, although this fuel is used in a fuel cell vehicle."
"To maintain the hydrocarbon base feedstocks in a scenario with great reductions of GHG, sequestration of CO2 in deposits in the crust of the earth would be necessary and is often discussed as technically not infeasible. The unavoidable consequence is, however, a distribution system for hydrogen, which we cannot see as the general future system (above). For GHG-reductions of the magnitude of 80-90%, only biomass-based fuels have such potential, as has been demonstrated in several of the studies...."
"...Further reduction of friction, pumping losses and heat rejection are other areas where certain scope of improvement remains. The maximum efficiency is foreseen to increase only marginally, from the level of today between 43 and 45% to about 46%. By the way, this mentioned level is the development target for 2004 in the US PNGV programme. A correction of the increase in fuel consumption due to cold start as received from the simulations in Advisor has been made, since the model apparently is not correct in this respect. (The same model as for petrol engines has been used, which is not supported by experimental data.) In order to fulfill future NOX emission limits - that are anticipated to be significantly stricter in the future for diesel-fuelled cars, presumably similar to petrol cars - a NOX storage catalyst will be necessary. There is some increase in fuel consumption associated with the NOX regeneration (this regeneration could be simultaneous to the regeneration of the particulate filter). An increase of the fuel consumption by 2% due to the regeneration has been anticipated, although recently published data indicate that this penalty might be reduced to less than 1%, provided that the sulphur content is below 10 ppm . An increase in the fuel consumption of the same order as above (2%) has also been anticipated for the diesel engines fuelled by other fuels than diesel fuel, since these engines must use the similar type of catalyst...."
"...Hybridisation appears to be a preferred way to increase the fuel efficiency and it seems that this potential is greater for combustion engines than for fuel cells. Fuel cells can be more efficient than conventional otto-engine powertrains, but the advantage over diesel hybrids is relatively small or nil...."
Well-to-Wheel Efficiency For Alternative Fuels From Natural Gas or Biomass, October 2001, Ecotraffic
"- The diesel CIDI HEV uses the least amount of total energy.
- The diesel CIDI conventional vehicle and the gasoline SI HEV yield roughly the same total system energy use.
- Among all of the crude oil- and NG-based pathways studied, the diesel CIDI HEV, gasoline and naphtha FP FC HEVs, and GH2 FC HEVs, were nearly identical and best in terms of total system energy use (Btu/mi)...."
- Compared to the gasoline SI (conventional), the gasoline SI and diesel CIDI HEVs, as well as the diesel CIDI (conventional) yield significant total system energy use and GHG emission benefits...."
"...The fuel cell system with reformulation has not so high potential compared to the hybrid system...."
"...Continuing to work on today's gasoline engine and its fuel will bring major improvements by 2020, cutting energy use and emissions by a third compared to today's vehicles. But aggressive research on a hybrid with a diesel engine could yield a 2020 vehicle that is twice as efficient and half as polluting as that "evolved" technology..."
"...Combining these two technologies could yield a promising medium-term vehicle: the hybrid-electric diesel. A diesel hybrid could indeed achieve an impressive fuel economy and could be superior, in terms of both GHG production and cost, to fuel cell vehicles...."
Source: Deliberating Diesels: Environmental, Technical, and Social Factors Affecting Diesel Passenger Vehicle Prospects in the United States, ACEEE, Report Number T032, James Kliesch and Theresa Langer, September 2003
-Sodium borohydride is derived from borax, which is abundant and widely available
-Sodium borate is a common, non-toxic household item used in detergents
-Sodium borate can be recycled into new sodium borohydride
The Rest of the Story
-To recycle sodium borate into new sodium borohydride requires reduction reaction in a kiln at 900oC under highly corrosive environment
-Coke or methane (CH4) is needed: CH4 + NaBO2 + (900oC) --> NaBH4 + CO2
-It takes more energy to make sodium borohydride than the energy released (or recovered) in the fuel cell..."
Source: Fuels of the Future for Cars and Trucks, Dr. James J. Eberhardt, Energy Efficiency and Renewable Energy, U.S. Department of Energy, DEER Conference, August 2002
"...Dr. Eberhardt also looked at smaller vehicles. He points out that if you use compressed hydrogen fuel cells with a typical passenger van, one-third of the total cargo space would be taken up by the fuel tanks. Once again - advantage diesel...."
"...Fuel cells have a lot of obstacles to overcome. A fuel-cell powertrain is 10 times more expensive to make than a conventional powertrain. At best, hydrogen is four times as expensive to produce as gasoline, according to the Department of Energy. Fuel-cell vehicles require an expensive new infrastructure to supply hydrogen to motorists.
And it is unlikely that the most viable fuel-cell vehicles will be pollution-free. Coal, natural gas and even gasoline are likely sources of producing the electricity needed to create hydrogen. They all contribute to pollution.
By contrast, diesel vehicles are a proven technology. Diesel cars in the United States get 48 to 75 percent better mileage than their gasoline counterparts...."
Source: The Detroit News, January 31, 2003
"...The problems with hydrogen are numerous. Even turning the gas into a usable form is not easy: extraction of hydrogen from oil, natural gas, water or biomass is energy intensive and expensive. Refinement and transportation then add to that energy bill. Storage is also problematic and refuelling a vehicle is potentially dangerous. Finally, fuel cell technology itself is still an expensive prototype curiosity. ..."
"...Two European researchers, Drs. Ulf Bossel and Baldur Eliasson calculated that it takes 1.2 to 1.4 units of conventional energy to make 1 unit of hydrogen....
...The Department of Energy estimates that it will cost the United States alone more than $1 trillion.... that's a thousand billion... to convert its infrastructure from petroleum and natural gas to hydrogen. ..."
"...The volumetric heating values are (1 bar, 25 C):
HHV H2: 11.7 kJ/liter
LHV H2: 9.9 kJ/liter
HHV CH4: 36.5 kJ/liter
LHV CH4: 32.9 kJ/liter..."
"...Hydrogen does not exist in nature in its pure state, but has to be produced from sources like water and natural gas. The synthesis of hydrogen requires energy. This process is always associated with energy losses. Hydrogen production by both electrolysis or chemical reforming is a process of energy transformation. Electrical energy or chemical energy of hydrocarbons is transferred to chemical energy of hydrogen.
Making hydrogen from water by electrolysis is the most energy-intensive way to produce the fuel. But it is a clean process as long as the electricity comes from a clean source. Less energy is needed to convert a hydrogen-rich energy carrier like methane (CH4) or methanol (CH3OH) into hydrogen by steam reforming, but the energy invested always exceeds the energy contained in the hydrogen.
Thermal losses limit the efficiency of hydrogen production by reforming to about 90%. Consequently, more CO2 is released by this "detour" process than by direct use of the hydrocarbon precursors. We assume efficiencies of 75% for electrolysis and 85% for reforming. About 1.2 to 1.4 energy units of valuable electricity, natural gas, gasoline etc., have to be invested to obtain one energy unit of hydrogen. But most of these source energies could be used directly by the consumer at comparable or even higher source-to-service efficiency and lower overall CO2 emission.
Upgrading electricity or clean hydrocarbon fuels to hydrogen does not provide a universal solution to the energy future, although some sectors of the energy market may depend on hydrogen solutions. The transportation sector may be one of them. It should be mentioned that it is considerably more expensive to produce hydrogen with electricity from water than thermally from fossil fuels. According to  it costs around $5.6/GJ to produce hydrogen from natural gas, $10.3 /GJ to produce hydrogen from coal, but $20.1/GJ to produce hydrogen through electrolysis...."
"...The engineer in charge of fuel cells for Honda, a company that is now leasing hydrogen fuel cell cars in the U.S., says that is will take at least 10 years to bring prices down to $100,000...."
"...Current fuel cell vehicles cost $1 million more than regular cars, largely because the proton-exchange membrane (PEM) fuel cells they use are so expensive. To make affordable cars, PEMs will have to cost under $50 per kilowatt (an internal combustion engine costs about $30/kW). Current PEM costs are 40 to 100 times greater...."
"..."We have reduced volume (of fuel cells). We have reduced weight. What we couldn't reduce so far is costs. Costs are still by far too high," he said...."
"...He also poured cold water on hydrogen fuel-cell vehicles that are seen by many automakers as the industry's next big technological breakthrough.
"The cost to build one fuel-cell car is about $800,000. Do the math and you'll see we'll have to reduce the cost of that car by more than 95 percent to get widespread market acceptance," Ghosn said...."
"...Liquid hydrogen works a bit better. GM's liquid-fueled HydroGen3 goes 250 miles on a tank roughly double the size of that in a standard sedan. But the car must be driven every day to keep the liquid hydrogen chilled to -253 degrees Celsius-just 20 degrees above absolute zero and well below the surface temperature of Pluto-or it boils off. "If your car sits at the airport for a week, you'll have an empty tank when you get back," Milliken says...."
"...I began to change my mind about hydrogen while researching a book over the last 12 months. After speaking to dozens of experts and reviewing the extensive literature, I came to realize that hydrogen cars still needed several major breakthroughs and a clean-energy revolution to be both practical and desirable...."
Source: "Lots of Hot Air About Hydrogen", Joseph J. Romm
"...According to the Department of Energy, "second generation" fuel cells are expected to have an energy efficiency of about 60 percent, so when they are used to convert the compressed hydrogen back into electricity only 30 percent of the original energy is recovered. In contrast, recovery of electrical energy stored in batteries can be as great as 80 percent. So storing electrical energy in batteries is between two and three times as efficient as storing it in the form of compressed hydrogen...."
Source: "Hydrogen-powered vehicles aren't a clean answer, professors say", Guest columnist - Apr 05, 2004, http://www.heraldtribune.com
"...A typical automotive fuel cell operates in the region of 0.55-0.75 volts per cell; the theoretical values for the HHV and LHV are 1.48 and 1.23 volts respectively. Using the values just given return efficiencies of 37% -51% for the HHV and 44%-61% for the LHV-but this is only the chemical-to-electric conversion efficiency; a car ultimately requires mechanical energy, not electrical, to move it and this is where the highly-touted fuel cell efficiency begins to take a turn for the worse...."
...PEM fuel cells are much less efficient than the ~50-70% hydrogen-to-output-electricity figure used by Lovins (as we have only recently discovered). An overall figure of ~35-50% is probably more appropriate for normal use when all accessory and parasitic losses are taken into account. At the same time, the figure that Lovins uses for gasoline engine efficiency is too low for modern gasoline IC engines combined with high-efficiency transmissions; roughly 25% is closer to the real efficiency and this figure is climbing steadily. But this does not completely negate his point that fuel cells used in light-vehicle applications should offer about 50-100% better economy (not the 2-3X claimed by Lovins) than gasoline engines, especially at low load. Diesel engines, on the other hand, are substantially more efficient than gasoline engines, approaching the lower bound of the fuel cell efficiency range (35-50%) and potentially capable of much higher efficiencies. In hybrid-electric applications, they can currently offer higher efficiency with acceptable on-road performance (currently a problem with fuel cell and hybrid vehicles). If high-speed compression-ignition engines can be developed to operate at very high compression ratios and near-instantaneous combustion (offering a close approximation to constant-volume combustion), probably on gaseous fuels (and possibly even hydrogen!), much higher efficiencies are possible....
...we see the diesel-electric hybrid as a far better choice for future transportation needs (once the U.S. has low sulfur fuel available in about 2006-2008) than either gasoline-electric hybrids or hydrogen fuel cells...."
"...the process of producing hydrogen via electrolysis releases roughly 24 percent more of these [greenhouse] gases than producing and burning gasoline in a vehicle....
...most hydrogen today is produced from natural gas via a process that is about 60 percent energy efficient (compared with 80 percent efficient for gasoline refining [and 84% efficient for diesel production and 320% efficient for soy biodiesel production]).... "
Source: Car and Driver, July 2005, pp 76-77
"...It has often been pointed out that we have an inexhaustible supply of water from which to derive hydrogen. However, this reaction, 2H2O + e = 2H2(g) + O2(g), requires a substantial energy investment per unit of water (286kJ per mole). This energy investment is required by elementary principles of chemistry and can never be reduced....
...The basic problem of hydrogen fuel cells is that the second law of thermodynamics dictates that we will always have to expend more energy deriving the hydrogen than we will receive from the usage of that hydrogen. The common misconception is that hydrogen fuel cells are an alternative energy source when they are not...."
"...As a physicist, I've been studying these problems for over 30 years, and it has become increasingly clear to me with each passing year that the "Hydrogen Economy" will never materialize and our only viable, long-term option is renewables. Compared to bio-fuels (bio-diesel, bio-gasoline, and ethanol), hydrogen has order-of-magnitude disadvantages in fuel costs, engine costs, and CO2 release that will not be solved in the next five decades....
...Bio-diesel from bio-methanol could compete with fossil diesel within 8 years, and the efficiency of the diesel hybrid will exceed that of the practical fuel cell...."
"...it is widely assumed that the ultimate solution to the energy problem will be via "the hydrogen economy". There are persuasive reasons for concluding that this is mistaken...."
"... even under the most optimistic conditions, hydrogen will support just 30% of the global stock of vehicles by 2050, according to the IEA study, Prospects for Hydrogen and Fuel Cells. As a result, transportation will require a mixed portfolio of fuel technologies, including biofuels and synthetic fuels....
...In the next few decades, hydrogen costs would need to be reduced three- to ten-fold and fuel cell costs by ten- to fifty-fold. Substantial improvements are also needed in hydrogen transportation and storage, and fuel-cell performance....
...However, hydrogen and fuel cell vehicles will only play a significant role under these favorable assumptions. If less optimistic assumptions are considered for technology development and policy measures, hydrogen and fuel cell vehicles are unlikely to reach the critical mass that is needed for mass market uptake. Competing fuels with lower infrastructure costs, such as biofuels and synthetic fuels derived from coal and gas, would play a larger part...."
"...The diesel engine was patented in 1893; 44 years after the invention of the fuel cell and nearly 20 years after the invention of the "Otto cycle" or the gasoline engine...."
"...Currently in the light truck industry, diesels are about 60 percent more fuel efficient and emit 28 percent less carbon dioxide (CO2) than gasoline engines...."
"...In a recent study, fuel cell expert Ulf Bossel explains that a hydrogen economy is a wasteful economy. The large amount of energy required to isolate hydrogen from natural compounds (water, natural gas, biomass), package the light gas by compression or liquefaction, transfer the energy carrier to the user, plus the energy lost when it is converted to useful electricity with fuel cells, leaves around 25% for practical use - an unacceptable value to run an economy in a sustainable future...."
Source: http://www.physorg.com/news85074285.html, Paper: http://www.efcf.com/reports/E13.pdf
"...At the very least, diesel vehicles will set a high standard for any other new technology to meet. It makes no sense to miss the benefits of a proven technology to wait and hope for fuel cell breakthroughs...."
"...According to Martens, turbo-charged diesel hybrid vehicles could approach "what a fuel cell does at a fraction of the cost." Additionally, they wouldn't require a brand new energy infrastructure...."
"...Hybrid cars, which combine electric motors with small petroleum engines, will outpace the environmental benefits of hydrogen fuel cell cars until at least 2020, according to a university study.
Hydrogen fuel-cell vehicles have low emissions and energy use on the road, but converting a hydrocarbon fuel such as natural gas or gasoline into hydrogen to fuel such vehicles uses substantial energy and emits greenhouse gases, the study said....
...But even with aggressive research, a hydrogen fuel-cell vehicle would not be better than a diesel hybrid in terms of total energy use and greenhouse gas emissions by 2020, the study said...."
"...Engineers say there is no technology on the horizon that would make gasoline engines as fuel-efficient as diesels...."
"... A survey of 5,200 consumers this year by J.D. Power and Associates showed strong potential for diesel. One-third told Power they would be likely or somewhat likely to buy a clean-burning diesel vehicle...."
"...Based on 4,473 survey respondents...
...Given a choice, more consumers indicate they would select a clean diesel engine over a hybrid electric engine to power their next vehicle, according to the J.D. Power and Associates Clean Diesel Market Assessment StudySM...
...if given a choice between a traditional gasoline, clean diesel or hybrid electric engine in their next vehicle, 27 percent of consumers said they would select a clean diesel, compared with 22 percent who would choose a hybrid electric engine and 51 percent who would select a gasoline-powered engine.
Given a scenario where fuel prices rise above $2.50 per gallon, 56 percent of consumers said they would select a clean diesel-powered vehicle, compared with 38 percent who would purchase a hybrid electric vehicle....
...Clean diesel technology was defined for survey respondents as "comparable performance of that of a gasoline engine, but the typical diesel noise, vibration and pollution have been reduced to that of a gasoline engine." Based on that description, 22 percent of consumers say they "definitely will" consider a clean diesel engine in their next vehicle purchase and an additional 44 percent indicate they "probably will" consider a clean diesel engine....
...Consumers expect to recover some of the price premium in fuel savings. Even if the fuel cost savings from clean diesel doesn't cover all of the incremental investment in buying the vehicle, 40 percent of consumers indicate that they still will consider a clean diesel vehicle for the lower fuel costs, tax credits or to reduce dependence on foreign oil...."
"...All things being equal in America, clean diesel engines are likely to win more customers than gasoline-electric hybrids, according to a study to be released this month by J.D. Power and Associates. Seventy-five percent of today's gasoline-engine owners would consider a diesel if the cost was the same, against only 59 percent for hybrids, J.D. Power forecasting director Walter McManus told a packed audience of 400 automotive engineers during an SAE panel discussion Monday. ..."
"...In a recent survey, Autobytel researchers were surprised by a rapid shift in opinion by drivers in favor of diesel. In the poll, released in January, 72 percent of respondents said they were "absolutely open" to buying a diesel vehicle, compared with 31 percent who answered in the affirmative in an April 2006 survey...."
"...As testament to the diesel engine's popularity, Ford reports its 6.0-liter Power Stroke diesel was installed in 63 percent of F-250/F-350 Super Duty pickups sold through the first nine months of 2004. GM's 6.6-liter Duramax diesel made up 44 percent of GMC Sierra HD 2500/3500 sales in the same time period (up significantly from just 12 percent in 2000) and 41 percent of the Chevy Silverado HD 2500/3500 sales (up from 33 percent in 2002). It appears that the most devoted diesel fans drive the Dodge Ram 2500/3500, where the 5.9-liter Cummins engine was sold in 80 percent of the heavy-duty lineup through September 2004 (up from 69 percent in 2002.)..."
"...Industry-wide diesel heavy-duty pickup and chassis sales from 1994 to 2006 grew at an average rate of nine percent per year, according to R. L. Polk & Co. In 2006, 69 percent of these trucks sold were diesel powered...."
"..."The Cummins Turbo Diesel is the engine of choice for 85 percent of Dodge Ram Heavy Duty customers," said Donoughe [Mike Donoughe, Vice President - Body-on-frame Product Team]..."
..."Not very many experts in this field have much faith in the future of gasoline engines," says Stephen Ciatti, a clean-diesel researcher at Argonne National Laboratory in Argonne, Ill. "Either diesel engines or fuel cells will be the likely contenders as the power plants for future transportation needs."...
"...Diesel's market share was nearly 31 percent in December alone, making it likely that the share will continue to climb in 2004, helped by the new generation of thrifty but fast direct-injection turbo diesel engines.
Diesel's market share in the UK, however, is still a lot lower than many other European countries where diesel fuel is much cheaper, due to lower taxes, than in Britain, where it is slightly more expensive than petrol at around 78 pence a litre...."
"...Europe's skyrocketing dieselization occurs even in the United Kingdom, where diesel fuel is more expensive than gasoline...."
"...The R10 is important for Audi commercially, for half the company's production is diesel-powered. Europe is the major diesel market - last month [Nov 2005] 42 percent of the new cars sold in Britain were diesels - but the technology has not taken off in the U.S., mainly because the low-sulfur fuel the modern European diesels need is not available. However, when the fuel does come to the U.S. manufacturers like BMW, Mercedes-Benz, and Audi expect that like British drivers, who were not as quick to accept diesels as their continental neighbors, American motorists will also find them attractive. Unlike the noisy and vibrating engines that spoiled U.S. diesel cars twenty-odd years ago, modern direct-injection diesels combine fuel economy with smooth and silent power...."
"...Europeans first choose comparably-sized diesels because of superior, "fun-to-drive" performance and quality perception, not because they are "cost-conscious" consumers..."
"...Although overall the price of diesel was 8% less than that of gasoline, in the UK, which showed an 8% gain in diesel sales, the price of diesel was 5% higher than gasoline...."
"Mercedes E 240 (gasoline)
Power: 130 kW
Torque: 240 Nm
Acc.: 9.1 s (0-100)
Speed: 236 km/h
FC: 10.9 l/100 km
CO2: 262 g/km
Mercedes E 270 CDI (diesel)
Power: 130 kW
Torque: 400 Nm
Acc.: 9.0 s (0-100)
Speed: 233 km/h
FC: 6.5 l/100 km
CO2: 172 g/km"
Source: Environmental and Health Impact From Modern Cars, May 2002 and August 2002 (DEER Conference),
Ecotraffic (Peter Ahlvic)
[FC = 10.9/6.5 = 1.6769 = 67.7% BETTER mileage with diesel E 270 CDI or
6.5/10.9 = 0.59633 = 40.37% LESS fuel usage
CO2 = 262/172 = 1.5233 = 52.33% more CO2 emissions with gas E 240 or
172/262 = 0.6565 = 34.35% less CO2 emissions with diesel E 270 CDI]
"...auction prices for VW TDIs run about $2000 higher than for gasoline cars, although VW prices the TDIs about $1000 higher than gasoline cars....
...ALG forecasts a premium of $2000 for a Mercedes diesel, while the suggested retail for a CDI model is only about $300 when comparably equipped. The balance, he says, is that ALG sees a premium of about $1300 in 36 months, which averages about a two percent higher residual value for the diesel models over equivalent gasoline models...."
"...Diesel cars and trucks hold their value better than gas-power vehicles do, according to Automotive Lease Guide, whose projections are considered definitive by automakers.
ALG's data show that a new diesel truck averages $4,926 more than the same truck with a gas engine. After a year, the diesel's worth $8,098 more than the gas model. After three years, $9,422 more.
That might not wipe out the truck's overall depreciation, but it more than repays the initial cost of the diesel option....
"...Direct injection almost certainly will be needed for fuel efficiency. For passenger cars, sport utility vehicles, and light trucks, there are two options: CIDI and SIDI. CIDI engines are inherently more fuel-efficient than are SIDI engines, but CIDI engines produce larger quantities of nitrogen oxides (NOx) and particulate matter (PM). Reducing those two pollutants to acceptable levels will require significant technical advances in fuel-system design and after-treatment technology. Since most after-treatment systems are extremely sensitive to sulfur contamination, reduced-sulfur fuels will probably also be essential...."
"...the initial cost of a diesel engine is higher than that of a conventional gasoline engine. One also needs to realize that even if CIDI technology completely replaced SIDI, refineries would still have gasoline as a byproduct that would need an outlet in the consumer market. For this reason it is nearly impossible to have 100% CIDI market share. Even though spark-ignited (gasoline) engines are less efficient than diesel engines and may never be able to achieve 80 mpg, marketplace demands probably will keep gasoline engines in a significant fraction of vehicles for many years. In addition to the limited gain in fuel efficiency that is possible with SIDI engines, other barriers to their use include durability and engine deposits. Also, an SIDI fuel system costs about 50% more than a port fuel-injection system...."
Source: Department of Energy
"...holds the promise of a nominal 60 percent efficient diesel engine..."
"...Diesel engines are already more efficient than gasoline engines (45 percent versus 30 percent), and further advances are possible (to 55-63 percent)....
"...Diesel engines are 30% to 40% more efficient than gasoline engines yet they can still maintain the power motorists like, France told the EPA's clean fuels conference. ..."
"...let's compare 2 Jeep Grand Cherokees sold in Europe, one with a diesel and the other with a gasoline powertrain. It's the same model, but the displacement is a bit different. The gasoline model has a 6 cylinder, 4.0 liter engine, versus just a 5 cylinder 2.7 liter diesel engine.
Listen to these numbers, which are straight out of Grand Cherokee literature:
1. Torque is 295 Newton meters for the gasoline; 400 for the diesel. For those non-engineers in the room, torque loosely translates to power. Which means, even with the smaller engine, the diesel is able to tow equal weight as the gas, but can tow it further and with greater acceleration and power. The diesel model clearly wins.
2. Carbon dioxide emissions are 600 grams per mile for the gasoline; 413 for the diesel. Again, diesel wins.
3. And, in U.S. terms, fuel economy is 15 miles to the gallon for the gasoline...and 24 miles to the gallon for the diesel. Translated into driving range, the gas vehicle can only travel 300 miles on a tank of gas while a diesel can go 480 miles. That's a 60 percent jump in fuel economy!
When it comes to performance, diesels make sense...."
"...The fuel efficiency of the diesel is directly related to lower emissions of carbon dioxide, which is a greenhouse gas and is associated with global warming. The conservative average is that diesels improve fuel economy by 25 to 40 percent. At Bosch, we believe that number is actually between 40 and 50 percent. That means that a diesel vehicle will, on average, use 40 percent less fuel to do the same job as a gasoline..."
"..."The diesel option will enable us to meet increased fuel economy standards of the future," said Kevin DeHart, vice president of diesel fuel systems at the Bosch Group.
DeHart estimates it costs $130 to $150 to improve diesel engine fuel efficiency one mile per gallon, while it would cost $300 to $500 to reach the same improvement in a hybrid electric vehicle. ..."
"...Recent advances in European high-speed automotive diesel engines...make such engines nearly ideal candidates for hybrid electric vehicle (HEV) applications...."
"...Hybrids might be one way to broaden the audience for diesels. Masatami Takimoto, the executive responsible for advanced engine design at Toyota Motor Corp., told the SAE audience that he expected hybrid powertrains to propel significantly more vehicles before the end of the decade. A diesel/electric hybrid would better than pure diesels in meeting the tough new air-quality standards that are being imposed in different parts of the world. "We are entering an age of fierce competition between clean diesels and hybrids," added Takimoto. "All the technologies should be out competing against one another. But hybrids are one step ahead with their cleanliness and their efficiency," he said...."
"...Cummins stated that its diesel engine development program demonstrates a fuel economy improvement of 50 percent-70 percent over gasoline engines...."
"...[Cummins] Fuel economy, advantage 44-49% [@ T2B5]..."
"...In 2002, VW Audi Group and DaimlerChrysler for the first time sold more diesel than petrol powered cars, according to a recent study by automotive technology developer Ricardo: "Diesel passenger car and light commercial vehicle markets in Western Europe".
Peugeot was very close to 50 per cent diesel sales in the same year. Overall, diesel penetration has reached 41 per cent, up from 28 per cent four years ago and remains on a continuing upward trend gaining an average 3 percentage points of penetration each year...."
"...As far as the hybrid engine technology that will be used, Ford said he expects Europe to use diesel-electric hybrids.Potential for hybrid diesels
And if the industry can drive acceptance of diesels in North America, then the hybrid diesel could be applicable worldwide...."
"...New technology for cleaner diesel engines and hybrid vehicles could cut gasoline use by 50 to 100 percent by 2030 without reducing vehicle weight or performance, the report said...."
"...Diesel engines developed with DOE support for light-truck applications, such as SUVs, pickup trucks, and minivans, are in the final stages of development. They will comply with stringent Federal Tier 2, Bin 5 emissions standards under Federal Test Procedure conditions. These diesel engines will double the combined city/highway mileage advantage over current gasoline engines and will cut carbon dioxide (CO2) greenhouse gas emissions by 37 percent. These vehicles will be on exhibit and will be demonstrated during the 2003 Ride and Drive session...."
"...dramatic advances in diesel engine technology mean that new compression ignition powerplants now offer an interesting alternative for US SUVs (sport utility vehicles) and light trucks, where high torque is a key requirement. Today, the driving force for the diesel market in the US will be the driveability benefits of high torque diesel engines coupled with 30 to 50% better fuel economy and - perhaps more importantly to American consumers - one third fewer tank refills...."
"....An evaluation of 24 matched pairs there [in Europe] found that...turbocharged, direct injection (TDI) diesel vehicles averaged 50 percent higher fuel economy...."
Source: Deliberating Diesels: Environmental, Technical, and Social Factors Affecting Diesel Passenger Vehicle Prospects in the United States, ACEEE, Report Number T032, James Kliesch and Theresa Langer, September 2003
"...Bedwell notes that fuel efficiency remains significantly better in diesel engines. Earlier expectations that direct-injection gasoline engines would erode this advantage have not materialised, and such hopes have been largely abandoned as further gains in diesel fuel-efficiency have been made. At the same time, diesels retain significant advantages in torque, and their earlier deficiencies in terms of emissions, maximum power and noise are close to being eliminated, though at a cost...."
"... However, advanced diesel engines will still be 50% more efficient than even next-generation spark-ignition ethanol engines, so bio-diesel may be even better...."
"... Cummins is maintaining the tremendous fuel economy advantages of its ultra-clean light-duty diesels--60% better fuel economy versus the comparable gasoline engine...."
"Piece of Mind from Mercedes
You don't have to be a mind reader to understand where Mercedes-Benz might be heading, thanks to the F500 MIND. Described as a research show vehicle, the F500 demonstrates that "We are far from reaching the limits of our technology," asserted Dr. Thomas Weber, the DaimlerChrysler board member in charge of research and technology. About the most conventional feature is the car's CL coupe-style grille. In fact, the four-door has a very coupe-like body. Like many Tokyo show prototypes, the MIND has no B-pillar, but the rear door can either swing rearward to create a yawning entrance, or be opened like a conventional car door. The "mobile research laboratory" features a diesel hybrid-electric powertrain that can operate in battery-only mode to reduce emissions and maximize fuel economy. The diesel pumps out a full 800 N-m of torque. The F500 boasts an active infrared laser night vision system, by-wire steering and instead of conventional foot pedals, there are pressure-sensitive plates. A "cone of sound" aims navigation instructions and warning sounds reach the driver, but cannot be heard by others in the vehicle. As typical for Mercedes, this show car hints at technology under development - "not for the next generation, but the one after that," acknowledged the automaker's head of passenger car operations, Juergen Hubbert."
"...Dr. Bernd Pischestreider, chairman of the Volkswagen Group, sees that kind of potential for diesels in North America.
"Diesels make much more sense than hybrids," he commented during a recent conversation at a diesel symposium hosted by Volkswagen in Wolfsburg.
"They cost less, perform better and provide almost the same fuel economy," he said. "And if, for some reason, you have to make a hybrid, a diesel hybrid is much better than a petrol (gasoline) hybrid."..."
"...But Fairbanks says some women he knows complain about the smell of diesel fuel. The longtime diesel advocate doesn't want any more obstacles to wider use of diesel engines in U.S. vehicles. ..."
"...And Congress is considering consumer tax breaks to make fuel-efficient diesels cheaper...."
"...Despite his possibly dated fears about female sensibilities, the 71-year-old Fairbanks remains bullish on diesel penetration of the U.S. light-duty vehicle market.
He predicts 10 percent by the 2007 model year - a much higher figure than other experts - with sustained growth after that. Diesels now account for about 0.2 percent of the U.S. light-vehicle market. ..."
"...EPA mpg test doesn't work for hybrids; procedure may be adjusted..."
"...An early poll of 30 2004 Prius owners showed most got between 45 mpg and 49 mpg...."
"...One devoted Prius owner in Minnesota, known as John1701a, says he averaged 45.4 mpg over nearly 60,000 miles in a 2001 Prius. He has since purchased the redesigned 2004 model and has raised his average to 47.1 mpg...."
Source: Autoweek, November 24, 2003
"...diesels appear to perform the best with respect to their label fuel economy, outperforming the label by 4.3%...."
...Hybrids fall short by a much larger margin, 8.2%...."
Source: http://www.epa.gov/fueleconomy/420r06017.pdf (page 16 of 179)
"...Combining an electric motor, a powerful battery and a diesel engine would give the best fuel economy possible for cars and light trucks, but it's the least likely combination to hit the market. The extra cost of the diesel and the electric system would limit sales so much that the fuel savings would be negligible. Not only that, Americans don't care much about saving fuel, McManus said. Another hybrid variation shown Monday was the first hydraulic hybrid sport-utility vehicle made by the Environmental Protection Agency. The transmission and transfer case were removed from the Ford SUV and replaced with a hydraulic drivetrain. The result: a $600 increase in the SUV's cost, but a 55-percent improvement in fuel economy, the EPA said.
Another 30 percent to 40 percent improvement in fuel economy is available if a small diesel engine replaces the gasoline engine. ..."
"...EPA officials said they have achieved a 90 percent improvement in the fuel economy of a Ford Expedition by installing a small diesel engine and hydraulic hybrid technology that the agency has been developing. ..."
Source: Automotive News
"...While the hybrid gasoline-electric powertrain is an interesting engineering exercise, it is still an impractical and not particularly economical method of building vehicles. The mileage for hybrids isn't all that remarkable either. With its high manufacturing costs, it's not a viable solution for mass-marketed vehicles...."
"...Americans deserve a fuel-efficient choice...."
Source: "Let's Rethink our Engine Types, Keith Crain, Automotive News, April 19, 2004, http://www.greendieseltechnology.com/News.asp?ID=14&link=
"...Just check out those power specs: The engine cranks out 368 lb-ft of torque from a measly 3.0 liters of displacement and at just 2000 revs, no less. That translates into some decent off-the-line performance. BMW claims a 0-to-62-mph time of 7.1 seconds for the 3715-pound car; that roughly matches the Mercedes-Benz C320's or the Jaguar S-Type's time. But neither of them can claim the following: We took the 530d on a weekend trip to Northern Michigan, a four-hour drive from suburban Detroit to the shores of Lake Michigan, not far from the Straits of Mackinaw. For the 525-mile jog northward and back, we stayed near the 85-mph mark, scooting around slower traffic when needed and paying absolutely no mind to minimizing the car's fuel consumption. But the fuel consumption sure paid mind to us. By the time we reached home, we had averaged almost 41 mpg...."
"...More illustrative, perhaps,is how the 530d stacks up against the fuel-economy leader on these shores, the Honda Insight. With an EPA combined 62.6 mpg, the Insight blows all comers away. However, in a yearlong test of the Insight, we managed a lot less than that, 52.61 over 14,963 miles of real-world driving.
If we're forced to be fuel conscious then: Given the Insight has no back seat, feels like a tin can, has perhaps the most irritating (low rolling resistance) tires on any car extant, and feels like it's stripped down to its skivvies, we'll gladly settle for 12 fewer miles per gallon in exchange for one of the best driver's cars on the planet...."
"...Reported the Deseret Morning News (Sept. 10 ): ...They are also always looking for ways to reduce emissions and increase fuel efficiency in vehicles, something [former EPA Administrator Mike Leavitt] said may be best accomplished by new technology that makes diesel engines less polluting than unleaded gas engines, as well as quiet and reliable in cold weather -- two problems that scare American consumers away from the diesel engines Europeans heavily favor. "If we were able to reach the penetration level that diesel engines have in European countries -- which I think we will in the next decade -- we could eliminate the dependence on foreign oil equal to what we import from Saudi Arabia," he said...."
Source: Diesel Technology Forum
"...Potential diesel efficiency (by 2014) ~ 60%..."
Source: Engine Maturity, Efficiency, and Potential Improvements, John W. Fairbanks, U.S. DOE, DEER 2004
"...Honda's new Accord 2.2 i-CTDi Sport has this week set no fewer than 19 world speed records and achieved 3.07 litres / 100 km (92 mpg [Imp]) fuel economy to boot...."
"Diesel vehicles improve fuel consumption by 30% compared to SI engines"
"Diesel vehicles have low fuel consumption (up to 78 mpg)"
"Diesel vehicles produce lower CO2 emissions"
"Diesel vehicles provide low service costs and high service intervals"
"Drivers enjoy driving diesel vehicles due to superior torque characteristics"
"...Today, diesel vehicles burn on average 30% less fuel and produce 25% less CO2 emissions than petrol vehicles...."
"...Diesel engines consume between 20 and 40 percent less fuel than their gasoline counterparts..."
"...replacing a gasoline engine with a diesel in a 3,000-pound car could result in a 30- to 40-percent improvement in fuel efficiency. Putting a diesel in a large sport utility vehicle could provide a 40- to 50-percent improvement in fuel efficiency..."
"...CIDI diesel engines burn 35 to 50 % less fuel than gasoline engines of comparable size, and they emit far less greenhouse gases (Carbon dioxides)..."
"...The diesel's high compression ratio and the lack of a throttle allow for high torque at low engine speeds and a consumption of 10% to 50% less fuel energy, depending on the operating cycle, than spark-ignited engines...."
"...Spark ignition engines are less efficient (30-50 %) than the diesel engines in similar applications...."
"...Diesel is typically 25 to 40 percent more fuel efficient than gasoline...."
"...we see further [diesel efficiency] potential of at least 10%. So from our perspective, the gap even between an advanced gasoline engine and a diesel engine will be in the ballpark of 30%...."
"...The energy equivalent fuel economy was 10.5% lower for the prototype LNG trucks compared with the newest diesel trucks. This is much better than results from previous studies of spark-ignition, heavy-duty natural gas trucks, which had equivalent fuel economies 27%-37% lower than diesel trucks over the same duty cycle*...."
"...Jerry Mcclain has toped 42 mpg last may in a 2003 [Dodge/Cummins] 2500..."
"...The 42 mpg truck was an 03 Dodge with the Cummins 5.9L common rail. Modifications included performance exhaust, propane injection, turbo mod, electronic controls and a wee bit of hydrogen injection. The rig still had a stock body, stock injectors and was (and still is) street legal. The 42 mpg was done on a track, so there was no "going downhill the whole time?". All the energy used, including the propane, was accounted for in calculating the 42 mpg rating...."
"...A permanent drop in world oil production will have serious consequences. In addition to the economic blow, there will be the psychological effect of accepting that there are limits to an important energy resource. What can we do? More efficient diesel automobiles, and greater reliance on wind and nuclear power, are well-engineered solutions that are available right now. Conservation, although costly in most cases, will have the largest impact...."
Source: NY Times editorial
"...substituting biodiesel for petroleum diesel reduces life-cycle CO2 emissions by 78%. B20 reduces CO2 by 15.66%..."
"...Unlike other biodiesel feedstocks, such as rapeseed, soy and palm, which require arable land to produce economic yields, jatropha grows on waste and marginal land and its planting will not displace essential food crops in developing countries...."
"...Biodiesel has the best energy balance of any liquid fuel. Every unit of energy needed to produce biodiesel results in 3.24 units of fuel energy. In contrast, diesel has a negative energy balance, requiring more energy to produce than is generated by the diesel fuel...."
"...Because diesel engines are more efficient than gasoline engines, overall fuel efficiency is higher. EPA projections show that if diesels accounted for a third of all vehicle-miles traveled in the country by 2020, the nation could save a million barrels of fuel a day and consumers could save more than $20 billion per year...."
"...In the battle of environmentally friendly biofuels for cars and trucks, biodiesel beats ethanol hands down...
"...The first comprehensive analysis of the full life cycles of soybean biodiesel and corn grain ethanol shows that biodiesel has much less of an impact on the environment and a much higher net energy benefit than corn ethanol...
"...Ethanol yields 25% more energy than the energy invested in its production, whereas biodiesel yields 93% more. Compared with ethanol, biodiesel releases just 1.0%, 8.3%, and 13% of the agricultural nitrogen, phosphorus, and pesticide pollutants, respectively, per net energy gain. Relative to the fossil fuels they displace, greenhouse gas emissions are reduced 12% by the production and combustion of ethanol and 41% by biodiesel. Biodiesel also releases less air pollutants per net energy gain than ethanol. These advantages of biodiesel over ethanol come from lower agricultural inputs and more efficient conversion of feedstocks to fuel...."
"...A student team from West Philadelphia High School in Philadelphia, PA, has taken top honors with its purpose-built hybrid vehicle, which uses biodiesel instead of gasoline..."
"...a biodiesel Volkswagen Passat, delivering 77 MPG over a 500-mile range...."
"...One key is selecting an algae with a high oil density - about 50 percent of its weight. Because this kind of algae also grows so fast, it can produce 15,000 gallons of biodiesel per acre...."
"...if all spark-ignition engines are gradually replaced with compression-ignition (Diesel) engines for running biodiesel, we wouldn't need 120 billion gallons of biodiesel to replace that 120 billion gallons of gasoline. To be conservative, we will assume that the average gasoline engine is 35% less efficient, so we'd need 35% less diesel fuel to replace that gasoline. That would work out to 78 billion gallons of diesel fuel. Combine that with the 60 billion gallons of diesel already used, for a total of 138 billion gallons. Now, biodiesel is about 5-8% less energy dense than petroleum diesel, but its greater lubricity and more complete combustion offset that somewhat, leading to an overall fuel efficiency about 2% less than petroleum diesel. So, we'd need about 2% more than that 138 billion gallons, or 140.8 billion gallons of biodiesel...."
"Outlook: Good. Biodiesel has a viable future as a major fuel for transportation. According to the National Biodiesel Board, production of biodiesel in 2004 was about 25 million gal., tripling to more than 75 million gal. in 2005. The trend is solidly upward, thanks to government incentives, the growing number of new diesel vehicles for sale and a grass-roots groundswell of support...."
"...A new analysis shows that the energy balance of biodiesel is a positive ratio of 3.5-to-1. For every unit of fossil energy needed to produce the fuel over its life cycle, the return is 3.5 units of energy, according to new research conducted at the University of Idaho in cooperation with the U.S. Department of Agriculture (USDA). The announcement of the increase-up from 3.2-was made today [February 6, 2008] at the National Biodiesel Conference & Expo in Orlando...."
"...Within just two years, Americans could be filling their cars with clean-burning biodiesel made from algae...."
"...The many engines developed to showcase the latest ways to reduce emissions and fuel consumption include the super-clean 248-horsepower V6 turbo diesel in the Mercury Meta One concept. The concept uses a variety of emerging technologies to produce a diesel that uses about 40 percent less fuel than a comparable gasoline engine and meets the toughest future emissions standards in the United States and Europe...."
"...Mercedes Benz' used such a feat to launch its new V6 CDI diesel engine. It had three cars picked at random off the production line, sealed, taken to a track in Texas and run flat out for 100,000 miles. Each E 320 CDI car ran flawlessly for 30 days straight while averaging 224 kmh (140mph)..."
"...The new Mercedes V6 CDI diesel engine, set to replace the existing five and six-cylinder in-line engines from summer 2005, has marked the start of its career with a string of world records. Fitted in three standard-production E 320 CDI models, the 165 kW/224 hp power plant covered the 100,000 kilometers, 50,000 and 100,000 miles respectively in world-record time* - and without any technical problems...."
"...Without stopping to refuel each of the unmodified CDI models covered a distance of 1039 miles (1672 km), which corresponds to a fuel consumption of 4.75 litres per 100 kilometres [49.52 mpg]...."
"...The savings resulting from a more widespread introduction of diesel engines in the USA would be gigantic. An increase in the market share held by diesel-powered cars and light commercial vehicles - from the current one percent to 50 percent as in western Europe - would reduce the annual level of American oil imports by approx. 133 billion litres!..."
"...The recent record-breaking run will give additional emphasis to the low fuel consumption of diesel models - 49.9 mpg is a phenomenal figure which many American consumers have previously considered to be absolutely impossible in this vehicle class...."
"...The hybrids do better in urban, stop-and-go driving while the diesels come into their own over the long haul, especially when towing or climbing grades...."
"...[the diesel] can easily outperform its gasoline rival while putting up fuel mileage numbers of 33.1 city and 52.3 highway for a combined 43.6 miles per gallon, 67 percent more fuel efficient than the 2.4L gas engine...."
"...While we found Precept to be little different in operation from a production sedan such as Chevy Impala, Ford Taurus or Honda Accord, the gauges in the instrument panel indicated that this hybrid mule truly will deliver 80 mpg on the highway. In fact, the mpg readout even topped 90 for some long stretches while we kept the speedometer at a steady 55 mph...."
"...General Motors presented the aerodynamic diesel-electric Precept, which obtained the highest PNGV average city/highway fuel economy rating of 79.6 mpg (gasoline equivalent)...."
Dodge unveils 72-mpg sedan
...[the] ESX3 would carry only about a $7500 cost penalty if produced in quantity for sale to the public. That would translate to an MSRP of about $28,500...."
"...Based on reported figures, the three PNGV diesel HEVs have the lowest unit energy consumption. In other words, they are most energy efficient in carrying vehicle load...."
"...On average, I estimate that PNGV diesel HEVs achieve about 174% gain in MPG - In a multiplicative incremental fashion, I estimate about 30% gain from dieselization, 37% gain from load reduction, 9% gain from engine downsizing, and 41% gain from hybridization.
On average, I estimate commercial gasoline HEVs achieve about 57% gain in MPG (on performance equivalent basis) - In a multiplicative fashion, I estimate about 9% gain from load reduction, 20% gain from engine downsizing, and 20% gain from hybridization.
- Comparing with commercial gasoline HEVs, my estimates imply that PNGV diesel HEVs get far better benefit from hybridization, but far less from engine downsizing...."
"...Development of this high thermoelectric technology mated with the beltless or "more electric" diesel engine wherein all the engine accessories are motor driven or the integrated starter/motor/alternator/damper could have diesel engine efficiency approach 60 percent efficiency! This could be achieved with a very wide range of liquid or gaseous fuels. This engine would reduce CO2 emissions by 50 percent as a "bonus."..."
Source: OVERVIEW OF VEHICLE EMISSIONS AND GREENHOUSE GASSES, John Fairbanks, Dept. of Energy, Office of Freedom CAR and Vehicle Technologies, Washington, DC 20585, International Conference on Energy, Environment and Disasters - INCEED2005, Charlotte, NC, USA - July 24-30, 2005
"...Average total consumption for the Mercedes over the 5,200-kilometer trip (3,232 miles) was 9.2 l/100km (25.6 mpg), while the Lexus came in at 10.2 l/100km (23 mpg)...."
"...The test result showed that the advanced diesel engine was far more fuel-efficient than the hybrid over long distances and only marginally less so in a city...."
"...The results showed that while the ML 320 CDI (165kW) returned an average fuel consumption of 7.62 litres/100km, the hybrid SUV (155kW) averaged 8.64 litres/100km...."
"...Ward's editors recently tested five diesel-powered vehicles that get from 16% to 67% better fuel economy than their gasoline-powered counterparts. My favorite, the BMW 535d, delivered spectacular performance and more than 28.5 mpg (8.4L/100 km) in real-world driving. My tiny gas-powered Mini Cooper S averages 24.5 mpg (9.6L/100 km)...."
"...the fuel savings from hybrids can be realized only under urban stop-and-go driving conditions, while diesels provide fuel economy benefit under any operating conditions, including highway cruising. The diesel-electric powertrain would be the most fuel efficient, but also the most expensive...."
"...On average, diesels consume 34 to 40% less fuel per mile than comparable gasoline cars. (50 to 70% more mpg)..."
"..."I think eventually there will be a combination of technologies and matrix," he said. "Diesel hybrids are a possibility in the future."..."
"...there is a market that could keep diesel applications trending upward indefinitely: the United States. Citing Americans' preference for big trucks and lots of torque, Barth says, "The U.S. should be a diesel market and no one understands why it's not." He dismisses the usual concerns about emissions and fuel quality as imminently fixable..."
"..."Diesels are all round superior to hybrids in terms of running costs, manufacturing costs, flexibility in town and highway, they are winning hands down. Hybrids' only plus? A marginal advantage in very heavy traffic congestion," said Schmidt...."
"...With all other things being equal, today's diesel engines are projected to achieve up to 40% higher fuel economy than today's gasoline engines, which is equivalent to about a 29% savings in fuel consumption. Since diesel fuel contains about 15% more energy and carbon than an equal volume of gasoline, a vehicle mile traveled with a diesel engine that has 40% higher fuel economy should reduce vehicle energy consumption and carbon emissions by about 18%. On a life-cycle basis, the total benefit of diesel engines is somewhat higher because there are higher per gallon energy losses for gasoline production than for diesel fuel production..."
"...Margo Oge, Head of the Office of Transportation and Air Quality at the US Environmental Protection Agency (EPA) presented the following figures back in March 2004: "If we had a light duty vehicle population that was one third diesels, that could save up to 1.4 million barrels of oil per day in the US, the amount of oil the US currently imports from Saudi Arabia. If we made these vehicles diesel hybrids, the oil savings would about double or up to 2 times the amount of oil Saudi Arabia ships to the US every day."..."
"...A diesel hybrid would be better than a gasoline hybrid. That's for sure. The cost effectiveness is what we've got to figure out...."
"...there is a feeling at Audi that traditional gasoline/electricity hybrids will not be able to stack up from an environmental or performance standpoint with diesel hybrid technology...."
"...This combination of power [diesel-electric hybrid] can deliver maximum fuel economy - up to 65 mpg, says Ford - without compromising performance...."
"...Folz has been dismissive about the current generation of petrol-based hybrid cars, saying as recently as the Frankfurt Motor Show in September that current diesel engines [were] more fuel efficient and emission-friendly than petrol hybrid cars...."
"...Citroen believes that the Diesel Electric hybrid is a much more effective method to reduce fuel consumption and emissions than petrol engined hybrids..."
"...Proponents note that diesels cost less to produce than hybrids -- about 15 percent more than a conventional gasoline car versus 25 percent more for gasoline-electric hybrids, according to Tokyo-based Yano Research Institute...."
"...Our hybrid technology can be combined with diesel or gasoline. And we are in the research stage on the diesel hybrid because that would be the most energy-efficient powertrain. The challenge here is primarily the cost side...."
"...DaimlerChrysler is becoming increasingly bullish about the prospects for diesel in the US, given the rising concerns about fuel economy here combined with apparently ongoing customer demand for size and performance.
J.D. Power and Associates forecasts that the market share for diesel passenger cars in the US, which currently stands at around 3.4%, will quadruple by the year 2015. Mercedes-Benz is convinced that once BLUETEC technology has established itself, this forecast will appear conservative rather than optimistic...."
"...So, how good is this diesel? Its 0-to-100 km/h time is just 1.7 seconds longer than the 350 hp V8, which hit 7.4 seconds on the same scale.
But what's amazing is its fuel economy - almost twice that of the gas engine (it works out to a nice round 1,000 km per tank of diesel fuel or an average consumption of 10.5 L/100 km). This motor is quiet, pulls hard and at idle barely gives away its identity in a whisper of sound...."
"...Honda Backing Away from Hybrids?
Recent reports have suggested that Honda is having second thoughts about hybrid powertrains. It's fair to say that CEO Takeo Fukui isn't rushing to fill the automaker's lineup with the high-mileage technology - at least not yet. While he told TheCarConnection.com hybrids have great potential, he stressed that it will be hard to push the technology into the mainstream "unless (production) costs come down." The outspoken executive said that while they represent an ecologically-friendly alternative, "there has to also exist a good business equation," and that is hard to justify right now, Fukui said. "We'll probably have more" than the current Insight, Accord, and Civic hybrids, he suggested, but when remains a question. Besides, he added, the hybrid "is not the only solution." Honda, Fukui said, is looking at a variety of other options, including ethanol and diesel powertrains, as well as hydrogen power...."
First, modern diesel vehicles are coming to be capable of meeting rigorous emission standards (such as Tier 2 standards, being introduced into the U.S., 2004-08). In this context it is possible without compromising environmental standards to take advantage of diesels' substantial mileage advantage over gasoline-fueled internal combustion engines.
Heavy penetration of diesels into the private vehicle market in Europe is one major reason why the average fleet mileage of such new vehicles is 42 miles per gallon in Europe and only 24 mpg in the US. Although the U.S. has, since 1981, increased vehicle weight by 24 per cent and horsepower by 93 per cent, it has actually somewhat lost ground with respect to mileage over that near-quarter century. In the 12 years from 1975 to 1987, however, the US improved the mileage of new vehicles from 15 to 26 mpg...."
"...Incentives for all should replace the current emphasis on automotive hydrogen fuel cells. ..."
"...GO DIESEL. With cleaner diesel fuel becoming available in the U.S. this fall, some automakers, including Volkswagen, Mercedes-Benz and Chrysler (DCX) are adding more diesel models to their fleet. Honda is adding diesels by 2010. Diesels tend to get better fuel economy than hybrids when usage is more cruising than urban stop-and-go. A Toyota hybrid, for example, doesn't make it from Washington, DC, to Detroit, a distance of more than 500 miles, on one tank of gas, as it gets about 38 miles per gallon. A Volkswagen Jetta TDI diesel-powered car, however, can make the journey without stopping, getting 45 mpg..."
"...According to a new study by TechnoMetrica Market Intelligence, a paradigm shift in consumer sentiment is underway that may make diesel vehicles as common in the U.S. as they are in Europe...."
"...the panelists generally expected to see diesels account for as much as a quarter of the U.S. market within the next 15 to 20 years...."
"...Yet here in the U.S., regulators have all but banned diesels, even though they could have an almost instant impact on our oil imports. If we see oil as an issue of national security, we've got to rethink our strategy and accept that the answer is a mix of options. Waiting for future tech that's years off is no more effective than relying on technology, like hybrids, that won't work for everyone...."
"...Global demand for diesel light vehicles is expected to nearly double over the next 10 years -- increasing from 15 million sales in 2005 to 29 million in 2015 -- according to J.D. Power Automotive Forecasting.(SM)
J.D. Power Automotive Forecasting projects the global market share for diesel-powered cars and light trucks will reach 26 percent by 2015 -- an increase from 18 percent in 2005. While Western Europe has been a key driver in the rapid growth of diesel vehicle demand for the past 10 years, increased demand from consumers in other regions will promote growth during the next decade.
"As a proven, cost-effective and 'off-the-shelf' solution, diesel has a head start over other emerging fuel-efficient technologies," said Alastair Bedwell, senior manager for J.D. Power Automotive Forecasting. "With energy prices at elevated levels and new regulatory pressure to improve light-truck fuel efficiency, a range of fuel-efficient alternatives to the conventional gasoline engine will be required. The United States and Canada are markets with enormous potential for diesel light-vehicle sales."
The diesel share of U.S. light-vehicle sales is expected to increase from 3.2 percent in 2005 to more than 10 percent by the middle of the next decade...."
"... However, advanced diesel engines will still be 50% more efficient than even next-generation spark-ignition ethanol engines, so bio-diesel may be even better...."
"...Our fuel station was offering up B20 biodiesel, 20 percent veggie oil, which means that from an environmentalist's perspective the German diesel didn't just beat the Japanese hybrids, it trounced them...."
"...Second part of a good plan is -- to confront high gasoline prices is to promote greater fuel efficiency. And the easiest way to promote fuel efficiency is to encourage drivers to purchase highly efficient hybrid or clean diesel vehicles, which, by the way, can run on alternative energy sources. Hybrid vehicles run on a combination of a traditional engine and an electric battery. The twin sources of power allow hybrid cars and trucks to travel about twice as far on a gallon of fuel as gasoline-only vehicles. When people are driving hybrids, they're conserving energy.
Clean diesel vehicles take advantage of advances in diesel technology to run on 30 percent less fuel than gasoline vehicles do. More than 200,000 hybrid and clean diesel vehicles were sold in the United States last year. It's the highest sales in history. Congress wisely in the energy bill expanded a tax credit for purchase of hybrids and clean diesel vehicles up to as much as up to $3,400 per purchase. That made sense...."
"...I also support biodiesel fuel, which can -- (applause) -- which can substitute for regular diesel in cars, trucks, buses and farm equipment. Last year I went out to see a biodiesel refinery in Virginia that's making clean-burning fuel from soybean oil. And it was a really interesting process to watch. I don't know if you know this or not, but they're able to use waste products like recycled cooking grease to manufacture biodiesel. In other words, research and development has lead to new alternative sources of energy like biodiesel. So that's one of the reasons why I signed into law the first ever federal tax credit for biodiesel producers. In other words, we're interested in addressing our energy security needs on a variety of fronts. It makes sense for the United States to have a comprehensive strategy to help us diversify away from oil...."
"...Diesels extract more energy from each gallon than gasoline engines, and less energy is lost as heat leaving the exhaust pipe than with a gasoline engine...."
"...Diesel engines are more powerful and fuel-efficient than similar-sized gasoline engines (about 30-35% more fuel efficient)...."
"...Robert Bosch GmbH is developing a common-rail fuel-injection system for diesels that would achieve efficiency-enhancing pressures of around 36,200 psi (2,500 bar) or even 43,500 psi (3,000 bar), far higher than current-production, best-in-class 26,100-psi (1,800-bar) systems, or next-generation 29,000-psi (2,000-bar) systems...."
"...At Audi, which builds diesels in Europe, the development of the US diesel market is being watched closely. ''We actually believe that if America wants to do something about its oil consumption, then diesel is the way," said Wolfgang Hoffmann, director of product management...."
"...Of the three models that Volkswagen sells in the U.S. with a diesel-engine option, the diesel versions accounted for 38 percent of Jetta purchases, 40 percent of New Beetle sales and 13 percent of Golf purchases. Diesel sales of the Golf were constrained by a dwindling supply before the coming switchover to a new version of the model, which is being renamed the Rabbit, Keyes said...."
"...VW says 38% of 9,929 Jettas it sold last month and 24% of the 33,699 sold in the USA the first four months this year have been diesels. Diesels use about 20% to 40% less fuel than similar-size gasoline engines, and diesel takes less energy to refine than gas...."
"...The retired physicist, inventor and fuel-efficiency advocate drives a modified diesel Volkswagen beetle that gets 65 miles per gallon in the summertime...."
"...With fuel consumption below 4-liters/100km (MVEG mix), the Astra Diesel Hybrid is projected to be 25 percent more fuel-efficient than comparable diesel models...."
"...'All of the (car makers) Japanese, European and American, are all very bullish on diesel,' says Bosch's Mr. Moulton. 'Even if they're not stating that.'..."
"...Diesels are shaping up to be an important component of Honda's future product strategy in the US...."
"...engineers are building a diesel engine for 2009 that Honda says will meet both new U.S. limits and more stringent California rules on soot and nitrous oxide emissions and still use 30 percent less fuel than gasoline models...."
"...Diesel engines could power as many as 30 percent of Honda Motor Co.'s vehicles in both the United States and Japan, a senior company official said..."
"...'When people think alternative fuel, they think "Prius," but there is more to the story,' said James Bell, publisher of IntelliChoice.com. 'Out of the 29 total 'Best Deal' winners, four are hybrids and three are diesels. In fact, our pick as the top luxury model is Mercedes' E320 CDI, one of the only diesel sedans available in the U.S.'..."
"U. S. EPA Technology Chief: Clean Diesels Best Way To Cut Oil Imports
...The powertrain technologies with "greatest likelihood for success" are, in order, clean-diesels, then series hydraulic-hybrids, then "high-efficiency alcohol fuel engines," then gasoline-fueled homogenous charge compression ignition (HCCI) engines, or "free-piston engines in series hydraulic-hybrid vehicles," although the latter two schemes will require more years of development, he cautioned. Besides consumer demands for better fuel efficiency, governments likewise are calling for actions to cut growing dependence on oil from politically unstable regions, he pointed out...."
"...Stronger support of diesel technologies makes more sense than the hype for hybrids or the euphoria over ethanol. If fuel efficiency truly is the goal, diesels can get there faster than any other technology available today...."
"...Now wake up because that perfect world of a clean, cheap and high-performance engine is almost here. In fact it is here, but you have to go to Europe to see it in action. It's diesel. And, for a couple of thousand dollars more, these engines get the same amount of horsepower with 30-percent better fuel economy and arguably lower emissions....
...Diesel engines are powerful and efficient. Diesel fuel is easier and cheaper to refine from crude oil. But diesels are more costly by $1,000 or more because of the advanced technology to make these engines accelerate more quickly...."
"...the company [Mitsubishi Motors Corp.] also is working on diesel engines.... ...He says hybrid technology, which uses a gasoline engine and one or more electric motors to power the wheels, is too expensive.
'We're targeting around 2010 for diesel engines for the U.S.,' Aikawa says...."
"...Modern, clean diesel engines will be a cornerstone of America's energy solutions, and clean, renewable biodiesel fuel will be critical to the success of diesel-powered vehicles in the U.S. market, a DaimlerChrysler executive [Loren Beard] says...."
"...Volkswagen diesels are almost legendary for their frugality, and our test Jetta lived up to the hype. The bad news: VW isn't offering diesel cars for 2007. The good news: VW has promised to build enough '06 models to keep shoppers happy until a redesigned diesel engine becomes available for 2008...."
"...It is no surprise then that the diesel is the better in terms of fuel consumption over our drive, but that it did so well, returning 4.5 litres/100km average, is a pleasant surprise.
The FSI Turbo also proves a surprise in returning 6.7 litres/100km.
Each car is a revelation, but the diesel comes out on top when it uses 33 per cent cent less fuel...."
"...'[Toyota's] success has been to put the idea in consumers' minds that hybrids are the only solution, but that's wrong,' says clean-diesel proponent Carlos Ghosn..."
"...In 2005, the [Audi] R8 [FSI] used 677 gallons to complete 370 laps of the 8.5-mile Le Mans circuit and could run 13 laps before draining the 23.8-gallon fuel tank. The following year, the R10 [TDI] burned 602 gallons of diesel (11 percent less), pitted every 15 laps, and finished 380 laps. Incidentally, not only was the diesel R10 17 percent more fuel efficient (the R8 got 4.6 mpg; the R10 5.4), but it was considerably faster. The R8's quickest lap in 2005 was 3:39.8. The next year, the R10's flier was 3:31.2. Now that's progress...."
Source: "Frank Kafka's Garage", page 164, Car and Driver Magazine, December 2006
"...Formation of this alliance indicates a recognition by Toyota, who has been a strong supporter and a leader in the gasoline-electric hybrid car technology, that it also needs a line-up of advanced, fuel efficient diesel cars...."
"Toyota Exec Says Diesel Prius Hybrids Possible..."
"...The difference between the diesel car of yesteryear and the Bluetec is nothing short of astonishing...."
"...Auto ignition is a prerequisite for really high efficient combustion....
...There is always a benefit coming from the auto ignition process versus a spark ignite ignition. Always a benefit. ...
...In our Lupo 3L TDI (3 liters per 100km fuel consumption rating) car we had the most efficient diesel engine ever shown. It had a peak efficiency of 51 percent...."
"...Studying the results, we see that, while the gas-electric hybrid achieved the best city, highway, and normalized combined gas-mileage figures, diesel is the most work efficient technology. This is primarily because, as the heaviest and quickest-accelerating car in the test, the diesel did the most work (814 BTU). That's 26 percent more that the lighter, slower Camry and 24 percent more than the lighter, almost equally quick VW. By achieving the second-best normalized fuel economy (27.8 mpg), trailing the hybrid by just 15%, the diesel's work-efficiency topped the field at 22,643 BTU-mpg--a narrow eight-percent lead over the hybrid. Accounting for the fuel energy reverses this finishing order, giving the hybrid a narrow 3.5% lead in carbon efficiency...."
Source: Motor Trend Magazine, May 2007, pp 99-100; http://www.motortrend.com/features/112_0705_alternative_fuel_technology/viewall.html
"...Diesel has a clear cost advantage over hybrid, even when fitted with the type of complex exhaust after-treatment technologies necessary to meet future, more stringent emissions regulations...."
"...For all three vehicle types [diesel, gas-hybrid, E85], the advanced diesel offers the highest savings over the life of the vehicle among the options considered...."Source: http://www.rand.org/news/press/2007/11/08/index1.html
"...Fred Rozell, a retail gasoline/diesel analyst for the Oil Price Information Service - a petroleum industry pricing news and information firm that supplies data to AAA, said the see-saw effect of gas vs. diesel prices will even out as production does. "I think eventually the majority of the U.S. (auto) fleet is going to be running on diesel," said Rozell, who is even more bullish on diesel's market penetration than JD Power...."
"...The study also finds that consumer consideration for purchasing clean diesel vehicles, which were newly introduced to the market in 2007, is at 23%. In 2006, only 12% of shoppers considered purchasing diesel vehicles...."
"...A diesel engine added about $1,000 to the roughly $50,000 sticker price of a new 2005 Mercedes E320 CDI sedan. Two years later, that option fetches $2,500 more at wholesale auctions than the gasoline-powered engine on the same model, the Black Book used-vehicle price guide reports...."
"...Diesel cars also tend to have far better resale values than their gas-powered equivalents. For example, a 50,000-mile 2004 Volkswagen Jetta GL with a 115-hp gas engine is worth $8875 at auction. That same car with the same mileage, but a 90-hp diesel engine is worth $13,950. That's $5075 - or 57% more....
...It's the same story for heavy-duty diesel trucks. A recent marketing study showed that after four and a half years of ownership, the average diesel truck is worth $4700 more than its gas equivalent, and has saved the owner more than $4200 in fuel. That $8900 difference more than offsets the truck's astronomical initial purchase premium (an average of $6600)...."
"...Edmunds.com has discovered that diesels present an even better choice for fuel-economy-minded consumers than hybrids...."
"...The light-duty diesel vehicles in production and in widespread use in Europe have already demonstrated a 30-40 percent reduction in fuel consumption, depending on engine size, compared with 2007 model-year gasoline engines..." [National Academy of Sciences]
"...The motivation for including light-duty diesel technology in the new report stems from the fact that the light-duty diesel vehicles in production and in widespread use in Europe have already demonstrated a 30-40% reduction in fuel consumption, depending on engine size, compared with 2007 model-year gasoline engines...."
Source: : National Academy of Sciences, "Assessment of Technologies for Improving Light Duty Vehicle Fuel Economy: Letter Report (2008)."
"...Downsizing a 2.0L diesel to 1.6L and improving the power with a 2-stage turbocharger and EGR would bring a 12% improvement in fuel efficiency, says Weissbaeck. Adding a stop/start micro-hybrid raises the improvement to 17%, and an electric motor attached to the engine or the gearbox would raise the improvement to 24% and 26%, respectively...."
"...Cummins currently shows a 7.2% improvement in fuel consumption compared to a 2007 baseline engine. There is additional room for system optimization on top of that, and the 10.5% target could be conservative...."
"...It is no surprise then that the diesel is the better in terms of fuel consumption over our drive, but that it did so well, returning 4.5 litres/100km average, is a pleasant surprise.
The FSI Turbo also proves a surprise in returning 6.7 litres/100km.
Each car is a revelation, but the diesel comes out on top when it uses 33 per cent cent less fuel...."
"...The V12 diesel, with a 6-liter (6,000 cc) engine closely related to that of the R10 TDI racing car-a triple Le Mans winner-delivers 368 kW (500 bhp) and develops a torque of 1,000 N-m (738 lb-ft) between 1,750 and 3,250 rpm.
Acceleration from zero to 100 km/h (62.14 mph) in 5.5 seconds and a capped top speed of 250 km/h (155.34 mph) equal the driving performance of a powerful sports car. Despite these performance data, the V12 diesel consumes an average of 11.3 L/100km (20.82 mpg US).
The gasoline-fueled 3.6 FSI, a V6 with a small cylinder angle, has a power output of 206 kW (280 bhp) and delivers 360 N-m (266 lb-ft) between 2,500 and 5,000 rpm. Its average fuel consumption is 12.1 L/100km (19.44 mpg US). The 4.2 FSI, a V8, delivers 257 kW (350 bhp) and 440 N-m (325 lb-ft) at 3,500 rpm. Its fuel consumption is 12.7 L/100km (18.52 mpg US)...."
"...after numerous tests of vehicles so equipped [with downsized gasoline turbo DI engines]..., we have yet to uncover a compelling real-world fuel-economy payoff. Ford is the latest suspect, spewing much hype regarding its version of this technology, called Ecoboost, which will be available in the 2010 Flex and Lincoln MKS and MKT...."
Source: "Displacement Downsizing - Where's the Fuel Economy Gain?" Car and Driver Magazine, July 2009, page 34
"...the 1.2 TSI consumes 5.5 L/100km (43 mpg US), with 129 g/km CO2....
...The 66 kW [TDI] variant is available in with the BlueMotion package. The resulting car offers fuel consumption is just 3.6 L/100km (65 mpg US), corresponding to a CO2 value of 96 g/km...."
"...The newly developed four-cylinder in the C 250 CGI BlueEFFICIENCY also uses direct injection. It achieves 150 kW/204 hp and offers 310 newton metres of torque. The saloon requires 7.4 seconds for the sprint from 0 to 100 km/h with the new petrol engine. The combined consumption amounts to 7.2 litres per 100 km (CO2 emissions 168 g/km)...."
(C 250 CDI BlueEFFICIENCY - 7.0 s 0-100 km/h; 5.1 liters/100 km; 134 g CO2/km)
"...the Taylors arrived Tuesday having set a new Fuel Efficiency Guinness World Record of 67.9 mpg [with a 2009 Jetta TDI], shattering the 58.8 mpg they set last year...."
"...The [BMW 320d EfficientDynamics Edition] sedan develops 163 hp (120 kW) between 3,500rpm to 4,200rpm and 360 N-m [265 lb-ft] of torque from 1,750 rpm to 3,000rpm, with fuel consumption of 4.1 liters diesel/100 kilometers (57.4 mpg US) and a CO2 rating of 109 grams per kilometer in the EU test cycle...."
"...Clean diesel technology has a potential well beyond gasoline systems..."
"...in the large-car segment, where gasoline port-injected V-8s are not uncommon, a much smaller turbodiesel with higher boost pressures, optimized exhaust-gas treatment and start/stop technology can more than double its fuel efficiency to almost 55 mpg (4.2 L/100 km), Rueger says...."
"...Fuel economy improvements and fuel savings per year for the hybrid vehicles in Table 26 vary considerably from about five percent for the larger, luxury hybrid vehicles to around 40 percent for several others. Similarly, fuel economy improvements for diesels range from 17 to 41 percent, and these vehicles also offer relatively high fuel savings...."
Source: http://www.epa.gov/OMS/cert/mpg/fetrends/420r09014.pdf (page 73)
"...In stark contrast to MotorWeek's observed numbers - they got 36.2 mpg in a stick-shift tester - our Jetta TDI reported a most impressive 47.0 mpg in trip-computer mileage. That's far better than even the car's 40-mpg highway rating, and we didn't drive any differently than we normally do...."
"...a 2005 study of the European refining industry demonstrated that, on average, refineries producing diesel emitted about one-half the CO2 emitted by refineries producing naphtha/gasoline streams...."
Source: http://www.tmaarc.org/Documents/LightDutyDiesel.pdf (page 26)
"..."Looking at gas mileage, it's probably even a tradeoff between hybrids and diesels because conventional diesels - not even in a hybrid vehicle - gets probably about the same gas mileage as a gasoline hybrid," noted Thomas Wallner, a research engineer at Argonne...."
"...Among engine types, diesel engines improved 9.8 mpg while conventional gasoline engines improved only 2.6 mpg over the period [2008-2012]."
"...A shift from gasoline to diesel engines following previous and upcoming European emission standards is consistent with long-term climate mitigation efforts, according to a new analysis by researchers from CICERO (Center for International Climate and Environmental Research, Norway), the University of Oslo and ETH Zurich...."
"...the Volkswagen Passat TDI ran away with this test even when the higher cost of diesel fuel is put into the equation. When you consider its well-equipped cabin, refined driving manners and grand size, the Passat's performance is even more impressive...."
"...unfortunately for those thinking the small turbocharged engine is the salvation to our fuel economy woes, this wasn't even close. At a steady 100 kilometres an hour, for instance, the A6 TDI did a fair impression of a Toyota Prius averaging just 5.1 litres per 100 kilometres [46.1 mpg]. Yes, a car weighing more than two tons and boasting six pistons managed a 5.1 L/100 km rating. The 2.0T's 6.4 L/100 km, while still impressive, was some 25% more profligate....
...Boosting the speed up to 120 km/h [~75 mph] just highlighted the diesel's advantage a little more. The TDI still sipped along at 6.0 L/100 km [39.2 mpg], an incredible feat for a large luxury sedan cruising at a supra-legal speed...."
"...In real world use, hybrids for many auto makers tended to underperform the lab results. Meanwhile, diesel engines tend to perform much better than the label-by almost 5 miles a gallon, according to The Journal's analysis. The spread is so significant that Mr. Grundler [EPA] has asked engineers to look into why the testing of diesels doesn't reflect real-world results more closely...."
"...Gasoline engines averaged fuel economy that was 0.7 mpg lower than EPA ratings, but diesel engines were on average 0.7 mpg higher. Hybrid
powertrains averaged 3.3 mpg lower fuel economy, although Consumer Reports noted that many owners report higher average fuel economy that's closer to EPA ratings...."
"...Fulcrum BioEnergy, the parent company of Fulcrum Sierra BioFuels, has applied for a new fuel pathway under the California Low Carbon Fuel Standard
(LCSF) for its process of converting municipal solid waste (MSW) into Fischer-Tropsch ("FT") diesel fuel...."
https://www.arb.ca.gov/fuels/lcfs/2a2b/apps/ful-ftd-sum-123015.pdf (description of process)
"...Specifically, [cylinder deactivation] benefits include increasing turbine outlet temperatures by 100 degrees C at all engine speeds due to reduction in air-fuel ratio,
which can result in higher aftertreatment efficiencies. Fuel economy gains at low loads can be as much as 30%...."
Source: Diesel Progress, June 2017, "Street Smarts"
"...Diesels offer a promising pathway for [GHG] compliance..."
Source: ICCT, WORKING PAPER 2017-08, http://theicct.org/sites/default/files/publications/Diesel-Engines_ICCT-Working-Paper_10072017_vF.pdf