A Growing Market
By our count, there are nearly 100 conventional hybrid, plug-in hybrid, battery-electric and diesel vehicles already in production, although some are built only for limited markets, primarily some or all of the states that have adopted California's zero emissions vehicle mandate, which are known as the ZEV states. Most of these cars have been introduced in the past five years, and things have slowed a bit after that flurry of activity. Automakers are still trying to figure out which technologies and fuels have the most promise in the race to slash oil consumption and greenhouse