Green and alternative-fuel vehicles are starting to become a large part of the automotive market and with gas prices continuing to rise, some are beginning to justify their higher price tags. But which type of alternative vehicle should you buy? The answer may depend on where you live and how you drive. We’ll look first at hybrids, then in future blogs, we’ll discuss diesel and ethanol.

Hybrids have returned the best fuel economy figures in Consumer Reports tests.

They combine the power of a gasoline engine with electricity from batteries driving an electric motor. Today’s hybrids never need to be plugged in.

There are two main types of hybrids on the market today: full hybrids and mild hybrids. Full hybrids run at low speeds on just electricity and don’t start the gas engine until the car reaches 10-20 mph in normal driving. Mild hybrids always augment some of the gas engine’s power when the car is moving, shutting it down when the car stops. Mileage varies widely.

In coming years, some hybrids may have a diesel instead of a gas engine to save even more fuel, and some will be able to be plugged in to maximize the electric mode.

Pros Hybrids are widely available, and don’t require any consumer behavior change. Some hybrids are also eligible for tax rebates, and in some states their drivers may to use carpool lanes, even with one occupant. The benefits are saving fuel, and reducing emissions.

Cons Most hybrids cost more to buy than comparable nonhybrids. And since fuel economy varies widely, not all hybrids live up to their reputation for super-high gas mileage. Some models use hybrid technology to boost performance instead.

For more information on hybrid vehicles, see How hybrids work. For more information on alternative fuels and fuel economy, see our Guide to driving green.