On Monday, December 20th, President Joe Biden committed to raising the average fuel mileage on new vehicles to 40 MPG in passenger cars and light duty trucks. EPA standards will be improved upon annually until the 40 MPG target is achieved in the year 2026. The most recent target was 32 MPG, set by the previous administration for the same year – 2026. This increase will undoubtedly have an impact on emissions moving forward, but do the automakers have enough time to accommodate the additional 8 MPG in just a few years?
Many of us, when searching for a new vehicle, consider fuel economy as a driving force in our selection process. But do we really know how these magic number are compiled? How are these vehicles tested, and under what conditions and are the published numbers even obtainable? In this brief blog we will dive into how the cars are tested and what fuel is used to arrive at each vehicles MPG we see on the window stickers and other online publications.
Vehicle testing environment
Contrary to popular opinion, our vehicles are not tested in the “real-world”, but rather an indoor laboratory setting and on a dynamometer. A dynamometer, or Dyno, is used in the automotive world to simulate driving conditions but also used as a calibration tool for onboard computers. Oftentimes the indoor conditions reflect a comfortable 70 degrees and flat surface – sure the Dyno can be altered to simulate a specific rolling resistance, but the purpose of this test is usually to provide a consumer-friendly MPG number under “ideal” driving conditions.
Accounting for different on road scenarios
Typically, the driver or in many cases the automated computer will produce different speeds during the driving cycle as to simulate a real driving experience. During each phase of testing there will be a different speed targeted for x-amount of time to account for city or highway driving. Generally, highway speeds are estimated based on 55 MPH which includes the best fuel economy on any passenger vehicle.
Fuel used in testing
Today, we assume the standard for our own use to be a gasoline product with 10% ethanol content. So – is that what is used in testing? The short answer is no. Our fuel standards are calculated from a conventional gasoline, or a gasoline product without ethanol. Aside from marinas, this conventional, non-ethanol-based gasoline is extremely difficult to obtain for consumers and is also as costly as premium grade in many markets. In general, the higher the ethanol content in our fuel, the less efficient the vehicle becomes from an MPG standpoint, but the more compliant the emissions become.
So, is the 40 MPG target any better than the previous 32 MPG target? Yes. However, is the fuel utilized to manufacture these numbers realistically obtainable? No. Is E10, E15 or E85 really going to reduce our MPG verse an unobtainable non-ethanol fuel? It sure will, but only because the engines are not designed to run on a higher ethanol-based fuel. Until the engines are altered to reflect peak operation with an ethanol-based fuel, the EPA requirements are a far cry from realistic expectations.
https://www.fueleconomy.gov/feg/how_tested.shtml
https://www.edmunds.com/fuel-economy/heres-why-real-world-mpg-doesnt-match-epa-ratings.html
‘A giant step forward’: Biden boosts fuel-economy standards, targets 40 mpg
