A closer look at the recently passed federal fuel economy rules highlights how electric vehicles complicate the familiar measures of mileage for industry and even consumers.
The Environmental Protection Agency and the National Highway Traffic Safety Administration last Thursday published final rules for automakers to meet fleet-wide requirements on fuel efficiency on light-duty vehicles. Fuel efficiency averages need to increase to 35.5 miles per gallon within six years, up almost 10 miles per gallon from now.
On the question of how electric and fuel cell vehicles contribute to the fleet totals, the EPA and NHTSA said the rules seek to strike a compromise between environmental goals and economic incentives to manufacture advanced auto technologies.
In calculating automakers overall fleet efficiency, the first plug-in electric or fuel cell vehicles produced between 2012 and 2016 will be credited as making no greenhouse gas contributions.
Over a certain number--200,000 or 300,000 vehicles produced depending on the total volume--greenhouse gas contributions will be calculated based on the net increase of upstream emissions from plug-in vehicles compared to the gasoline production. The tailpipe emissions from all-electric or fuel cell vehicles are considered zero. (Click for PDF, page 36 for advanced technology incentive program.)
That method for calculating the pollution generated by light-duty vehicles was created in response to input from environmental groups and industry, according to the rules document.
But the apparent compromise has brought criticism from different sides, underscoring how plug-in electric and fuel-cell vehicles raise a fresh set of questions around fuel economy.
The Alliance of Automobile Manufacturers said automakers should only be regulated on the pollution from the operation of vehicles.
"There is no precedent for holding companies responsible for the CO2 generated by electric utilities. We do not determine what happens from the plug to the utility plant," Gloria Bergquist, representative of the Alliance of Automobile Manufacturers, told USA Today. "It's unfair to base our compliance on what is entirely outside our control."
At the same time, there needs to be a system to recognize that electric vehicles do contribute to greenhouse gases, the Union of Concerned Scientists told USA Today. "The issue is really: we want a true accounting of emissions...If substantial credit is given, it should not continue (forever)," said Jim Kliesch from the Union of Concerned Scientists.
Meanwhile, regulators and the industry are working on ways to express the fuel economy of plug-in vehicles, such as the Chevy Volt and Nissan Leaf, to consumers when those cars come out later this year and early next year.
The sticker for the Mini E, for example, promotes the energy efficiency with kilowatt-hours per 100 miles as well as an equivalent of miles per gallon of gasoline, according to Hybridcars.com.