By 2025, passenger cars and light-duty trucks in the U.S. must meet Corporate Average Fuel Economy (CAFE) fleet standards of 54.5 miles per gallon (MPG). And, between 2017 and 2025, vehicle manufacturers are required to achieve annual efficiency gains of 5% and 3.5% respectively. While the goals are clear, the path to achieving them is not. So how will automotive manufacturers get there?
According to a report from the Environmental Protection Agency (EPA), technological innovation remains the primary driver behind vehicle improvements in C02, emissions and fuel economy. And, as Automotive News recently pointed out, despite the fact that today’s models are heavier and more powerful than they were just six years ago, fuel efficiency continues to increase due, in large part, to the “rapid adoption of new powertrain technologies”.
As we know, advances in technology are rarely linear and often come in steps. Each technology has its own inherent limits that are determined by physics. As a technology starts to approach its physical limit, a law of diminishing returns takes over—each incremental improvement comes at higher and higher cost. Once the limit approaches, significant advancements can only be made by a new approach that offers a step-wise improvement.
Take Achates Power, for instance. We recognized the inherent efficiency benefits of the historic opposed-piston, two-stroke engine. We also recognized the original engine’s limitations: poor emissions and oil control. But, by understanding the need to balance innovation and economics, we were able to bring this proven architecture into the 21st century by applying the latest technologies in combustion processes, electronics, mechanics and fluid dynamics.
So why is this important? Take, for example, the fuel efficiency improvements that the top vehicle manufacturers have introduced over the past two decades. Then, look at the current combined city and highway average fuel economy for 2013: 24 MPG. Concentrate on diesel-powered models, with their 30% fuel efficiency advantage over gasoline vehicles, which has helped make them the powertrain of choice in Europe. Then, compare these engines to the Achates Power opposed-piston engine, with its demonstrated ability to meet the most stringent emissions standards while still delivering fuel efficiency benefits of more than 20% compared to the best diesels on the road. Add to that the fact that the Achates Power engine is lighter, less complex and, as a result, less expensive to manufacture. Exciting prospect, isn’t it? This is especially true when you consider that it makes the 54.5 MPG CAFE target attainable.
At Achates Power, we’re committed to economically and environmentally sustainable transportation. With the commercialization of our engine, we can reduce GHG emissions and significantly improve fuel economy while helping vehicle manufacturers meet CAFE requirements at a lower production cost.

Clean Diesel Engine Engine Design Fuel Efficiency Standards