CAFE 2025 Regulations Are Achievable with Improved Gasoline Engines

In the recently released Corporate Average Fuel Economy (CAFE) draft Technical Assessment Review (TAR) the EPA concluded “the standards can be met largely with more efficient gasoline powered cars...” (LINK) We agree, we will meet, and exceed, future fuel economy and emissions reduction standards with advanced gasoline and diesel engines.

The Achates Power Opposed-Piston Engine has already been shown to achieve industry-best fuel economy gains of 30-50%, significant emissions reductions, and does so more cost effectively than any other solution. With engine programs in development with 12 leading engine manufacturers, we believe the Achates Power Opposed-Piston Engine will provide the foundation to meet the existing and future fuel economy and emissions regulations. As compelling as our engine’s efficiency advantage is, the Achates Power OP Engine will also be less expensive than predicted $1,000 increase from the 2021 baseline that the OEMs currently expect.

The CAFE draft TAR confirmed what many of us in the industry know; we can meet and exceed future fuel economy and emissions requirements with the advanced engine technology in development today. The regulations will help to drive further advancements in and adoption of engine technology, which will benefit everyone. Continuing towards these regulations will help protect the environment by improving fuel economy and reducing emissions, while providing consumers affordable cars and trucks that meet their needs. A no compromises solution.

CAFE 2025

CAFE 2025: Fuel Economy and Emissions Standards for 2025 (Image created by the White House)

10 thoughts on “CAFE 2025 Regulations Are Achievable with Improved Gasoline Engines

  1. Your engine development is very impressive. The recent announcement that you will have a 2.7L combustion ignition gasoline engine in a truck sometime in 2018 is exciting. One question I have is, are you testing ethanol blends in that engine? Will it run well on E15 or higher ethanol? The much lower fuel consumption of the engine along with the lower carbon intensity of ethanol would be a huge leap forward in greenhouse gas emissions.

    • Robert – thanks for the comment. We see no problems running the Opposed-Piston Engine on blends of ethanol, or any bio-fuel (i.e. bio-diesel, DME, etc.) for that matter.

  2. I’m involved in the development and conversion of the internal fleet (2.100 vehicles and machines) of Copenhagen City (Denmark – EU). We are only a small player but up-front in the international field of cities that want to act now in terms of CO2, NOX and PM emissions.
    I saw your engine design and I can’t wait to see when this will enter the global market. We have great troubles finding drivelines for heavy transport and large machines that are able of lowering emission since nearly all is diesel driven. We therefore look into high blend metanol, HVO, GTL and biogas solutions. So far biogas is very expensive both in usage, service and aftersales. Too expensive compared to the actual Well to Wheel (WtW) reductions. HVO has some interesting capabilities in reducing both NOX and PM as well as CO2. But the CO2 WtW aspect is somehow to oversee, since the market for HVO in Scandinavia is under great pressure and the LUC effect is actually reducing the positive CO2 effect. So we are at the moment left to focus on GTL (reducing only NOX and PM from 8-46 % according to our own tests at a minimum price increase of 5 %.
    Most OEM haven’t yet certified GTL yet, but is underways with this. Next think is a methanol project we are about to look at.
    For light duty transport and for small medium sized machines battery electric seems to be the way to go (excavators on +5 tons, front wheelers on 4 tons, small and medium sized trucks up to 18 tons as whell as large vans will within 2020 over go to BEV drivelines. First in 2022 solid state battery solutions will be on the market, slowly turning around the whole market. But there are some years ahead just yet.

    Question 1: Do you see any possibilties there in running on high blend methanol (like the Chinese are doing now – appr. 15 % of them).
    Question 2: Do you see any possibilities in making applikations like range extender solutions at the moment?

    Kind regards

    David Marc Gurewitsch
    Fleet Development

    • Hi, David –
      Thank you for your interest in Achates Power. To answer your two questions:

      Question 1: Do you see any possibilities there in running on high blend methanol (like the Chinese are doing now – appr. 15 % of them).
      Yes. In fact, there are a lot of good reasons to think methanol is excellent fuel (link to this article: The efficiency advantages from our engine comes from the architecture and design, not the fuel. We’ve run diesel, JP-8, natural gas, and gasoline in our engine, all with excellent results.

      Question 2: Do you see any possibilities in making applications like range extender solutions at the moment?
      Yes. The OP engine is an excellent range extender engine, for a number of reasons.
      Since each cylinder in our opposed piston engine is almost perfectly balanced, our range extender engine can be a single cylinder. This adds to the efficiency advantage of the OP engine since it improves the surface area / volume ratio advantage of the combustion chamber vs. any multi-cylinder conventional engine. All the other efficiency advantages remain.
      Also, the ability to achieve rapid catalyst light-off will be important to minimize tailpipe NOx emissions when the engine turns one. Studies by Southwest Research and others show that most of the tailpipe NOx is emitted in the first 600 seconds of operation, when the exhaust gas is below 250 C. Once the exhaust gas is hot enough for effective catalyst operation the tailpipe NOx comes down substantially. The OP engine can reduce the time to critical temperature to about 50 seconds, providing significant NOx advantage.
      Moreover, the single cylinder OP REX engine has few parts, and therefore packages well and is cost effective.
      We’ve been invited to speak on this topic at the SAE Range Extender conference in November (link to

      Addressing your issue more broadly, we expect our diesel heavy-duty truck engine will meet California’s ultralow NOx standards (0.02 g / bhp-hr, 90% below U.S. federal limits) while also generating 15% less CO2 than federal standards. We are working with an number of commercial vehicle companies now, but if you have a good relationship with a supplier send them our way.

  3. This sounds to me to be a wonderful wonderful development for mankind I hope you have plans on expanding this engine into multiple cylinders for it’s a fission C purpose

  4. The loss of valves and cams breaks my heart and my wallet smiles.
    With the simplifications would it be possible to start the engine in reverse and run it? (A la steam train.) could this change the style and purpose of the gear box? Would reverse crankshaft prohibit this thought?
    What loss of continued torque would occur at low revs on a single cylinder model?
    Is there any advantage of building this with horizontally opposed pistons?

  5. Will there be a developement for marine power. Will they be developed for salt water use. Especially for diesel fuels.

    • William,
      Development for applications is all done by engine OEMs, who are our customers. We don’t have plans to manufacture an engine.

  6. Could HCCI with compression ignition be applied to your opposed piston engine? I’ve seen some designs with a small chamber that is compressed further just as the piston reaches TDC, this could be accomplished with a mating chamber/’piston’ on top of opposing pistons. This initial small combustion increases pressure, causing the rest of the lean air/fuel mixture to ignite. The lean HCCI ratio and ‘all at once’ ignition results in very low emissions, and high power, as the expansion occurs so fast that the pressure is exerted on the full power stroke.

    If this could be accomplished with the Achates opposed piston two-cycle design, the engine would be so simple. No valves, no spark plug, and only port (not expensive direct) injection. Maybe operation would be limited to a more narrow RPM range, but this would not be a problem for a generator or a series/parallel hybrid automobile.

    • Ken, thanks for the comment. Many fuel savings, and emissions reduction technologies, can be applied to our Opposed-Piston Engine architecture. We can’t necessarily comment on your example specifically.

Leave a Reply

Your email address will not be published. Required fields are marked *


This site uses Akismet to reduce spam. Learn how your comment data is processed.