Fuel-saving know-how is already at hand...car buyers just have to start buying.

As the tastes in cars shift and the price of gas raises, market economics could deliver the fuel-efficiency increases we've been missing. The last time gas prices were $3, the average vehicle got 21 miles to the gallon. Vehicles have gotten more fuel-efficient, according the the EPA, however its the car buyers who have wanted other things than to travel further for the gallon. American drivers are purchasing bigger, heavier, faster, and quieter vehicles like SUVs and minivans, which now account for 50% of vehicles sold in the U.S., that is more than double the amount in 1981. The EPA says that if today's vehicles were the same, in terms of average weight and speed, as those in 1981, but had today's more fuel-efficient engines and transmissions, they would see a 30.5% improvement in fuel economy.
However, the current gas prices just might change the current taste for vehicles. According to AutoData, SUV sales are 11.2% lower than last year and General Motors is extending its "Employee Price" incentive to include 2006 large trucks and SUVs, a sign that those vehicles need sales help. A recent poll done by the Kelley Blue Book and Harris Interactive shows that 59% of current vehicle shoppers have let gas prices influence their decisions on purchasing a vehicle and the resale value of SUVs is dropping. As the market shifts back toward cars instead of trucks, that could allow fuel-saving technologies that are already in use to work in favor of using less gas.