I say "hybrid car"; you say "Prius." Toyota's fuel-sipping sedan has become iconic for gasoline–electric hybrid technology, so much so that the model seems to cast a green aura over the world's largest car company. Owners can burn less gas when they drive, and so release fewer carbon dioxide (CO2) emissions. During the past decade, Toyota has controlled around three quarters of the U.S. hybrid market, with worldwide sales of the Prius and luxury Lexus hybrids nearing two million vehicles—more than half of them Priuses.

The U.S. auto press recently had a chance to take the latest (third-generation) 2010 Prius on a test spin through the budding vineyards of Napa Valley, Calif. My instant review: It's improved and not nearly the generic "people pod" transportation it used to be. The new model rides reasonably well and power is prompt, if not overwhelming. And the redesign is still quirky enough to attract true believers and "eco-couples" that comprise the base Prius ownership, albeit still appealing to average buyers who want a regular car. The big benefit is, of course, striking fuel efficiency—the best among sedans on the market.

Despite the introduction of the new version, Toyota will continue to sell the earlier, second-generation Prius, as well. This unusual move to offer both cars probably indicates the mounting competition the company's management now perceives in the maturing hybrid vehicle market.

Here are 10 things you should know about the Prius.