This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American
Car manufacturers in the United States have surpassed greenhouse gas emission standards for the 3rd year in a row, according to the U.S. Environmental Protection Agency. Fleet-wide fuel economy has also increased by 26% over the past decade to a record high of 24.3 miles per gallon (mpg).
In their reports “The Greenhouse Gas Manufacturer Performance Report” and “Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends: 1975 through 2015”, the EPA concluded that auto manufacturers exceeded federal emission standards by 13 grams of carbon dioxide (CO2) per mile driven for cars and light trucks (2014 model year) – the equivalent of a 1.4 mpg improvement in fuel economy.
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On an individual company level, all major U.S. auto manufacturers – except for Kia and Mercedes – outperformed their standards for the 2014 model year. Of note here is that Volkswagon was not included in this analysis because of the on-going investigation (to read more about VW and #DieselGate, see Tali Trigg’s series here, here, here, and here on Plugged In).
The additional savings have been supported by faster adoption rates for fuel-efficient technologies than had been anticipated, says the EPA. According to Christopher Grundler, the EPA’s Director of the Office of Air Quality and Transportation:
“It’s clear that our [greenhouse gas emission] standards are working, spurring technology and innovation, and we are on track to achieve significant greenhouse gas reductions.”
However, the EPA cautions that, while fuel economy is on the rise, so is the market share for trucks, which get fewer miles to the gallon than cars. All told, truck fuel economy reached a record 20.4 mpg in 2014, which was a 0.6 mpg increase from the previous model year. But, this savings was offset by a 5% increase in truck market share in the same period.
The EPA goes on to say that these greenhouse gas emission standards for cars and light trucks have already prevented 60 million tonnes of carbon dioxide emissions from being released into the atmosphere.