Where to start:

• Research the pros and cons of continuing to drive the car you already own.
• Use Car Talk’s Auto Advisor to describe your preferences and receive new-car recommendations.
• Visit the Union of Concerned Scientists’ Hybrid Center Comparison Chart for hybrid car recommendations.
• Read Consumer Reports’ free list of the most fuel-efficient cars it has tested. With a subscription you can research gas mileage, and other details, by vehicle category.
• Check out Yahoo! Autos’ Green Center list of the top 100 cars by green rating.
• Use Fueleconomy.gov‘s nifty comparison tools to research mpg, air pollution, annual petroleum consumption, and cost-to-fill-at-the-pump info. for specific cars.

More about: Buying a fuel-efficient car

With the average cost of gas topping four dollars a gallon at times in 2008, fuel-efficient cars’ popularity is zooming. Concern for the environment leads to the same place.

If you’re in the market for a car and thinking fuel economy, the first place to look is in your own heart: What do you need a car to do? The greenest car for you is the one with the best mileage that fits your needs.