The Union for Concerned Scientists has come out with an article about the history of fuel economy regulations, and the current effects of the regulations.
In 2002 Johns Kerry and McCain offered an amendment to the Energy Bill to increase gas economies to 36 mpg for both cars and light trucks by 2015. If this had been enacted, our country would be saving about 2 million barrels of oil a day, the same amount that we import from the Persian Gulf. Instead, Congress gave the Bush Administration's National Highway Traffic Safety Administration (NHTSA) control over deciding fuel economies. In 2003 the NHTSA decided to increase average fuel economies for light trucks by 1.5 mpg for 2007 models. This is a smaller improvement than what auto companies have already announced they will be making by 2005. That's right, Detroit is more fuel conscious than our government.
The average fuel economy of cars is at a 21-year low, with standards being frozen since 1996 (remember, Republicans have controlled the House during this whole time). Finally in 2001 (when Democrats had some control of the Senate), Congress agreed to start studying fuel economies again, though no enactions have been made to date. Be sure to thank your Representative, Senator, and Administration in November.
(Thanks to my brother for sending me this article.)