By the Blouin News Business staff

Will U.S. cars really reach 35mpg by 2025?

by in U.S..

Getty Images

Getty Images

Last week the progress and challenges of increasing vehicle fuel economy were highlighted by several sources. WardsAuto published its Fuel Economy Index rating for U.S. light-vehicle sales, which reached 25.2 miles per gallon in October — just a 0.2% increase from a year ago. On the other end of the spectrum, the U.S. Department of Energy’s website released its top 10 list of fuel-efficient cars for 2016, dominated by electric vehicles that get an equivalent of 100 mpg or more. In between is the U.S. National Highway Traffic Safety Administration’s Corporate Average Fuel Economy (CAFE) target for passenger cars and light trucks: 54.5 mpg by 2025. Because the legally required testing is outdated (i.e., driving at relatively slow speeds, and excluding energy-using devices like air conditioning), the equivalent real-world average by 2025 will be approximately 35mpg. But even attaining that increase will be no easy task.

When the government issued the CAFE regulations in 2012, it estimated that reaching them would save about 4 billion barrels of oil and reduce greenhouse gas emissions by the equivalent of approximately 2 billion metric tons over the lifetimes of light duty vehicles produced from 2017–2025. (Separate targets for heavy vehicles from 2021-2027 are estimated to lower CO2 emissions by approximately 1 billion metric tons, cut fuel costs by about $170 billion, and reduce oil consumption by up to 1.8 billion barrels over the lifetime of the vehicles sold under the program.) These are huge savings, and well worth pursuing even with low oil prices.

Although electric vehicles are extremely efficient, they are still much more expensive than the average American consumer can afford, so they will not be the salvation of the passenger fleet anytime soon. And regarding gasoline-fueled vehicles, there is concern in the auto industry that much of the low-hanging fruit in fuel economy innovation has already been picked. (Among the innovations of recent years is the reduction of vehicle weight by using lighter materials like aluminum and improved engine efficiency through technologies such as gasoline direct injection and cylinder deactivation.)

But some companies believe the post-2020 standards could be far more difficult to reach. And the CAFE standards are not set in stone — their midterm review is coming up in 2016 and 2017, opening up the possibility that pressure from automakers could get U.S. regulators to water down some of the requirements. All of this makes future progress uncertain.

But according to, average fuel economy is already significantly higher in Europe (36.8 mpg) than in the U.S. As such, existing technologies being used by European carmakers could help raise U.S. fuel economy. Nick Molden, CEO of U.K.-based Emissions Analytics, estimated that the U.S. could raise its fuel economy by 4.6 mpg by switching to smaller 4-cylinder engines and other downsizing technologies. Adopting other fuel-efficient European technologies like direct injection and variable cylinder technology could add a further 3.7 mpg, and adding more diesel engines to the fleet would raise fuel economy by an additional 3.6 mpg.

And after the VW scandal, deceiving regulators is no longer an option. So in order to verify progress (in both fuel economy and emissions) real world measurements are needed. In this light, French weekly Auto Plus reported in October that major auto brands considerably understate real-world fuel consumption. The magazine said it tested fuel consumption of more than 1,000 models and found that on average it was 37.2% higher than what was reported by automakers.

At the time, AFP wrote:

Volkswagen has found itself in trouble for software that cheats official tests and lets many of it diesel engines spew out up to 40 times more pollution than permitted. The scandal highlighted the fact that car certification testing is done in laboratories under controlled conditions that are far from those on the roads. Auto Plus found that recent Volkswagen and BMW diesels were consuming 55 to 65% more fuel than reported. The discrepancy in fuel consumption for some diesel engines compliant with the latest pollution requirements was up to 74.3%.

And Auto Plus’s findings were spot on; in fact, last Tuesday VW admitted that it had understated the fuel consumption of 800,000 of its cars sold in Europe.

To resolve this disconnect, beginning in 2017 new European Commission rules will require real world vehicle emission tests. Independently, PSA announced in October that it will measure the real world fuel consumption and CO2 emissions from its Peugeot, Citroen, and DS brands. It hopes to publish the results, which will be vetted by an independent body, next spring.

Sooner or later the U.S. will follow suit. Washington should also resist any pressure from automakers to relax the CAFE standards, because even with today’s low gasoline prices, better fuel economy still saves money and reduces greenhouse gas emissions. The targets are attainable in the current timeframe, and there is enough global competition to prevent automakers from overcharging consumers in order to do so. And crucially, making the investments now will help insulate consumers from sticker shock if fuel prices increase again.