CNET editors' hybrid car buying guide

If you've filled out the above calculator and got a surprising answer--say, your current 1998 Honda Civic gets better mileage than the Ford Escape Hybrid--consider this: Hybrid technology goes a long way toward improving mileage and lowering emissions, but it's not the silver bullet. Whether or not a vehicle carries batteries, its weight is always an issue. While the Escape Hybrid weighs nearly 4,000 pounds, the poky ol' Civic probably weighs a mere 2,500 or so, and that missing 1,500 pounds makes it a lot easier to achieve good mileage.

Also, consider the reason behind the hybrid technology in the car of your choice. Toyota obviously intends the Prius, for example, to be a thrifty, ecoconscious car that boasts one of the best mileage ratings in the industry. The Chevrolet Silverado Hybrid, on the other hand, gets only 18mpg in EPA tests. That is, however, 2mpg better than the gasoline-only version, representing a 13 percent gain in efficiency. That 13 percent will make a difference at the pump.