Full, Assist, or Mild: Which Hybrid is for You?

So, you've been stuck with the same 1996 Chevy for the last ten years, and it's finally time to donate your car to charity and move up to something more modern. You're considering buying a hybrid car, but which one? Hybrid technology has been exploited by some bandwagon car manufacturers, and therefore, not all hybrids are the same. Some hybrids have great gas mileage, while others barely do any better than their gasoline-only counterparts. How do you know what's what?
Before you head out for a test drive, do your research on edmunds.com or autobytel.com, and look at the different hybrid cars available. Pay attention to the type of engine each hybrid has. You'll notice that some cars seemlessly blend electric and gasoline power, while others us the electric motor for very little. Of course, the more your car uses the electric motor, the less it's using gasoline, so look for:

• Full Hybrids -- Full hybrid cars are capable, if your driving style and conditions are right, of running solely on the battery. They typically have a gas engine, an electric motor run by a battery that charges itself when you brake, and some sort of computer that tells the car where to get power from under what type of driving conditions. The Toyota Prius and Highlander, Ford Escape, Lexus RX 400h, Mercury Mariner, and restyles Honda Civic hybrids all utilize this technology.
• Assist Hybrids -- Assist hybrids can't run on electric power alone; they use the electric motor as a way to increase torque from the gasoline engine. Assist hybrids have smaller battery packs than full hybrids, and they are able to have smaller gasoline engines without sacrificing power. The Honda Insight and the first-generation Honda Civic Hybrid are example of assist hybrids.

Other hybrid vehicles don't use the electric motor to assist the gasoline engine at all. These "mild hybrids," such as the Chevrolet Silverado Hybrid, have a glorified starter that allows the car or truck to turn itself off at stoplights without the radio or air conditioning turning off. You will see a slight fuel economy improvement with a mild hybrid, but nothing like what you'd get with a full hybrid or assist hybrid. [Source: Hybrid Cars at About.com, Wikipedia]