Real-Time Fuel Economy

The New York Times called it “one of the great fictions of American life,” akin to the notion that fast food is a healthy and nutritious alternative to home-cooked meals. It’s window-sticker fuel economy, which is almost always hopelessly optimistic. If the sticker says 30 mpg on the highway, expect 25 when headed down a mountain with a tailwind.

The Environmental Protection Agency (EPA) has tested cars under ideal conditions: on level ground, with no bumper-to-bumper traffic or running air conditioners or heaters. This unrealistic system had been unchanged since 1984. But it’s finally time for a little truth-telling. Last December, the EPA announced a new formula for calculating fuel economy that will reduce the numbers on the stickers eight mpg for city driving and 12 mpg for the highway, with the impact falling most heavily on small cars and hybrids. The changes will begin with 2008 models sold during the 2007 calendar year.

As an example, the vaunted Toyota Prius won’t change mechanically at all, but instead of 55 mpg in combined city and highway driving it will now show 44 mpg. Consumer Reports has long advocated this change, and spokesperson Ann Wright, a senior policy analyst, calls it “a very positive step forward. We’ve recommended a few other things, but they made the most obvious changes to give more realistic numbers. This recognizes the changes in driving conditions over 30 years. For instance, in the 1970s, air conditioning was only on upscale models, there was less congestion and universal 55-mph speed limits.”

Wright points out an interesting anomaly. The new calculations will be reflected on window stickers, but the National Highway Traffic Safety Administration (NHTSA) will still use the old numbers to calculate automakers” compliance with the federal Corporate Average Fuel Economy (CAFE) laws. Getting NHTSA in line might require either congressional action or an administrative order. But obtaining the latter from a fuel economy-phobic President Bush may prove difficult. Former Congressman Sherwood Boehlert, an environmental leader in the House, calls this a “shame” and “unacceptable.”