By Jim Henry

10 Ready-For-Prime-Time, Fuel-Saving Technologies

Fuel economy is a game of inches, and watts, and pounds. Automakers are faced with a new federal mandate to reach a Corporate Average Fuel Economy standard of 35 mpg by 2020, vs. actual performance of about 22.5 mpg today. Facing that kind of pressure, they're trying everything to squeeze out 1 mpg here, and 1 mpg there. Here's a list of existing, working technologies that are either already on the market or about to be, which the car companies are in the process of expanding exponentially. Breakthrough technologies like fuel cells may be over the horizon, but these practical measures will have much more impact, in the short to medium term.