Fuel Economy: Why the U.S. Continues to Trail Europe

When it comes to fuel economy, the United States is behind. Some say, way behind. In Europe, for example, consumers have been buying fuel-efficient, diesel-powered vehicles for decades. While diesel sales are growing here— increasing by 26% from 2011—they are still far short of European sales. In fact, diesel cars account for nearly 55% of passenger vehicle sales in Europe. So, why the big difference?
Availability: Diesels are widely available in Europe and much of the rest of the world. Most every car for sale in Europe is available with a diesel engine option. The customer can choose. For most of the last decade, there have been few diesel engines offered in U.S. cars. As a result, most U.S. consumers don’t know how good diesels are and the few who do know, usually can’t find the car they want with a diesel engine because they just aren’t being offered by most manufacturers.
Regulations: U.S. emissions regulations were developed on the basis of gasoline engine emissions characteristics. In Europe, emissions regulations were developed separately for diesel engines and gasoline engines. Both U.S. and European emissions regulations for both gas and diesel engines reach the same near-zero emissions requirement, but the implementation schedule of European emissions regulations allowed sufficient time for manufacturers to develop the emissions solutions while U.S. regulations didn’t. This put diesels at a disadvantage in the U.S.
Pump Fuel Prices: U.S. fuel prices have contributed to slow demand for fuel-efficient diesel engines. Since the average price of fuel (both gasoline and diesel) is much lower in the U.S. than in Europe, American car buyers are less concerned about fuel economy.
Government Actions: What the government does affects what manufacturers and customers do. Electric vehicles, hybrid vehicles, natural gas vehicles and fuel cell vehicles all receive substantial and preferential ongoing government support. Generous tax incentives—such as the $7,500 federal tax credit for electric vehicles, HOV lane access, special benefits in the CAFE calculations and government subsidized loans—each move the marketplace and disadvantage diesel-powered products. As Volkswagen recently announced, “it’s time for the U.S. government to include clean diesel in its ‘all of the above strategy’ for greening U.S. roads”.
Despite all of that, conditions are improving and so the time is right for the U.S. to play catch up. Availability is up—new diesel car and light truck models are being introduced, one after another, with a 2014 line-up that includes the Audi A6, A8 and Q5; BMW 328d; Chevy Cruze Diesel; Jeep Grand Cherokee EcoDiesel; and Ram 1500 EcoDiesel. Additionally, the most challenging CAFE legislation in decades can be more easily met with highly practical and cost-effective diesel engine technologies rather than very expensive electrification technologies. The few diesel-powered vehicles available for sale in the U.S. will soon pass the multitude of expensive electrified vehicle sales in combined market share. It’s already happening. In August, diesel sales increased nearly 42% from the year before.
With more diesels available, U.S. consumers will have more options to test drive and buy a diesel over gasoline, hybrid and electric vehicle options. So their perceptions of diesels are bound to change. For example, diesel cars from the 1960s were awful (but efficient) products. The combination of turbochargers and high pressure common rail direct fuel injection (found in all current diesel cars) and great low-end torque (inherent in the diesel combustion process) provide an excellent driving experience. The vision of diesel engines belching black smoke is also a thing of the past. Thanks to ultra-low sulfur diesel fuel and exhaust aftertreatment technologies, diesel-powered cars now meet the same emissions standards as gasoline-powered vehicles.
While some things may never change, it’s clear that we need the cleanest, most efficient and most cost-effective engines in our vehicles. Today, that means the few diesels that are being offered. Soon, there will be more, including innovative technologies—like the Achates Power opposed-piston, two-stroke diesel engine—that will take us to the next-level of performance: cleaner, more efficient and still more cost effective.
Achates Power was just named a semi-finalist in the Securing America’s Future Energy (SAFE) “Energy Security Prize”. The competition recognizes the top three U.S. organizations that are developing technologies to significantly reduce long-term U.S. oil consumption. To learn more or to vote as part of the public voting period, which continues through October 11, 2013, click here.

10 thoughts on “Fuel Economy: Why the U.S. Continues to Trail Europe

  1. Hi,
    Nice to see people doing R&D on two-strokes. I have had a few Peugeot diesel cars and the performance was comparable to gasoline cars, even a sporty model with sporty seats, however the mpg was superior. A neighbour is an automotive engineer and worked on the new Renault range of diesel engines. On the downside of modern diesels, he pointed out that they are now more complex than gasoline engines. Also modern engines now need soot filters. They are still noisier at idle and low speeds. The opposed piston diesel using modern technology offers to vastly improve in efficiency and complexity.
    I am sure you are aware of the Commer (Rootes) TS3 opposed piston diesel engine which was made from 1954 to 1972 in the UK. It was 3 cylinders and 3.2 litres and pulled an articulated truck using about half the fuel of similar trucks. As a five year old boy I would sit at a road near where I lived waiting for the laden Commers to pull up the hill from the docks, just to hear the unique magic noise from the engine. One of the worst business decisions in the past 50 years was when Chrysler bought Rootes and dropped the engine ordering the prototypes and design documents of ready to produce update, the TS4, destroyed. Look at Chrysler now and they could have been world leaders in diesel engines if they continued R&D on the TS3 and TS4 over the past 45 years. The engineers hid some engines and one is now reconditioned and running in New Zealand, awaiting installation in a truck. Look up Rootes TS4 on Youtube. I hope you carry on where Roots left off.
    In June 2013 the world’s first series hybrid plane flew, using a Wankel engine to only turn the generator. The Wankel was chosen because of the power/weight advantages. This opposed piston diesel has a power/weight advantage to normal 4-strokes and looks suited to series-hybrid applications.
    Some questions, which I hope you do not mind having a go at:
    1. Where do you see this engine? Constant speed running, at its sweet efficient spot, turning a generator in a series-hybrid? Having the engines off when a vehicle is halted it eliminates the rough diesel idle vibration and noise, as per the Prius.
    2. What are its immediate applications. Cars? trucks, buses, vans, trains, light planes, military uses?
    3. Are you using an electric scavenging pump, rather than mechanical? Electric engine ancillaries offer advantages over meshed gear or belted mechanicals.
    4. Are you looking into a gasoline version?

    • John:
      Thank you for your interest in Achates Power and for your insight into the historical Rootes-Lister TS3 opposed-piston engines. With regard to your questions:
      1. Where do you see this engine? Constant speed running, at its sweet efficient spot, turning a generator in a series-hybrid? Having the engines off when a vehicle is halted eliminates the rough diesel idle vibration and noise, as per the Prius.
      Opposed-piston, two-stroke engines can replace almost any diesel engine currently on the market and dramatically improve fuel efficiency in the process. Constant speed application can ensure that the engine is running at its best efficiency, but Achates Power opposed-piston engines show a relatively flat fuel consumption curve, which means the brake-specific fuel consumption (BSFC) changes less as speed and load change compared to a conventional, four-stroke engine. Therefore, it offers an even bigger benefit in applications that operate at many speeds and loads, that is, over a drive cycle, like trucks, passenger cars, etc.
      2. What are its immediate applications. Cars, trucks, buses, vans, trains, light planes, military uses?
      Due to the fact that it’s clean, significantly more fuel efficient and costs less to manufacture than the best engines on the road today, the Achates Power opposed-piston engine is suitable for a wide range of applications. While commercial vehicles will save on the order of $15K a year on fuel using our engine (at $4 gallon or more in Europe), the need for improved fuel economy is widespread and includes passenger cars, military vehicles, UAVs and marine power generation. This is, perhaps, best demonstrated by the fact that we have recently signed contracts with the U.S. Army Tank Automotive Research, Development and Engineering Center (to develop the Next-Generation Combat Engine) and Fairbanks Morse Engine (to reduce emissions and fuel consumption of their proprietary diesel and dual-fuel engines).
      3. Are you using an electric scavenging pump, rather than mechanical? Electric engine ancillaries offer advantages over meshed gear or belted mechanicals.
      An electric engine accessory drive offers similar benefits for our engine as it does for a four-stroke engine. Currently, we are using mechanical-driven accessories. However, we can—and will—take advantage of the benefits of electric engine accessories. As with a conventional, four-stroke engine, we have to evaluate these accessories from a cost-benefit perspective before adopting them. Our main interest is to develop and optimize the specific architecture and combustion system of the opposed-piston, two-stroke engine in order to reduce fuel consumption and increase power. We will use other commercially available technologies to further the fuel economy benefit.
      4. Are you looking into a gasoline version?
      Our engine can run on a variety of fuels, including biofuels. We’ve demonstrated the architectural efficiency benefits using diesel and natural gas. Diesel, of course, is more energy dense (by weight and volume) and more energy density equals better MPG.
      David Johnson

  2. Hi,

    I am a high school student doing a school science essay. My teacher told us to write an essay on fuel economy and I have a question: why the average fuel economy for passenger vehicles in the U.S./Canada is around 30 mpg? Is that a fairly low or high fuel consumption in comparison to other countries? What controls/regulates the fuel economy standards?

    Thank you!


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