Surveys of owners of hybrid-powered automobiles show that, on the average, each is saving about 408 gallons of fuel a year _ or, based on recent gasoline prices, about $900 annually. That's according to surveys of almost 1,000 people by Carnegie Mellon University engineering, science and public-policy students.

The surveys also showed that owners of about 200 diesel-powered cars are saving 388 gallons of fuel each year even though they drove 22 percent more miles than they had in the past.