The most straightforward way to reduce GHGs from motor vehicles is to simply mandate greater vehicle fuel economy. This translates more or less directly into reduced CO2 emissions, but may or may not significantly affect emissions of other GHGs such as CH4, N2O, and refrigerants. In the U.S., Corporate Average Fuel Economy (CAFE) standards have been constant since the mid- 1980s, despite considerable technological progress over the past twenty years. Standards for light trucks have been increased slightly in recent years. Other nations and regions, such as the European Union, Japan, and China, also have vehicle fuel economy standards that are currently somewhat more stringent than those in the U.S. In the U.S., the shift toward purchases of light trucks and sport-utility vehicles has resulted in an actual decrease in on-road vehicle fuel economy, from a peak of 26.2 miles per gallon on average in 1987 to 24.6 miles per gallon in 2004.