The vast majority of the vehicles sold in the U.S. run on gasoline, but the number of green alternatives keeps growing. February 9, 2009 Hybrids. Even with a plethora of Priuses on the road, hybrids make up only slightly more than 2% of vehicles sold. Supply is tight because of battery shortages, and sales for most models have been so-so because of the price premium. SPECIAL: 2009 CARS SLIDE SHOWS: Best Cars for 2009 FULL STORY: 2009 Cars: Deals Are Insane TOOL: Compare More New Models METHOD: Choosing the Top 2009 Cars EXTRA: How to Drive Home a Bargain MORE: Kiplinger's Car Buying Guide A larger, more fuel-efficient Prius debuts for 2010, and this spring Honda launches a new hybrid with an old name, the Insight. The Insight will sell for less than the $22,000 Prius, making it the lowest-priced hybrid on the road. This spring, Ford delivers its 2010 Fusion hybrid, which gets 41 mpg in the city -- 8 mpg better than the Toyota Camry hybrid -- and can work in electric-only mode up to 47 miles per hour. It will start at about $27,000. Electric vehicles. If you believe the hype, the Chevrolet Volt plug-in hybrid will transform the Detroit automaker. But the Volt may cost as much as $40,000 when it is introduced late next year. The Toyota Prius plug-in will be introduced later this year, but will initially be sold to commercial customers only. Many other carmakers have either a plug-in hybrid or an all-electric vehicle in the works, including Chrysler, Ford, Mitsubishi and Nissan. BMW recently introduced its Mini E, a two-seater version of the Mini Cooper. For now, 500 Mini E's are being distributed to select customers in California, New Jersey and New York. For the latest tax breaks on alternative-energy vehicles www.fueleconomy.gov.