As gas prices rise, so does interest in fuel-efficient vehicles, especially gas-electric hybrids. Dealers say sales this year are up about 50 percent.

But despite gasoline prices hovering around $4 per gallon, hybrids may not be the most cost-effective choices for many drivers. Hybrids are more expensive than traditional cars, and buyers often pay more for their vehicles than they would save in gasoline over several years.

The good news: Drivers can now choose from hybrid models from Ford, General Motors, Toyota and Honda that all could earn back their price premiums in less than 10 years. Four of five can save you enough in gas to offset the higher cost in as few as six years. That figure could climb higher if you considered corporate twins such as the Mercury Mariner for the Ford Escape or the Saturn Aura for the Chevrolet Malibu.

The bad news: Some of the top performers a similar Cleveland Plain Dealer analysis last year fell a few notches. Last year, Honda's Civic hybrid looked as if it would take about three years to earn back its higher cost. In this year's analysis, the Civic takes more than four years.

Andrew Chiarelli, manager of alternative-fuels vehicles for Motorcars Honda and Toyota, said he has sold 50 hybrids since the beginning of the year himself. The dealerships' sales are way up too, he said.

"The interest in the (Toyota) Prius never really dropped," Chiarelli said. The biggest increases in sales have come from the Honda Civic and the Toyota Camry hybrids. He also has sold some Toyota Highlander sport utility vehicle hybrids.

Four major factors have changed in the past year: Gas prices are much higher; new federal testing standards provide more-realistic fuel economy targets; more companies are offering hybrids; and tax breaks for some models have expired.

Honda's Civic hybrid was a victim of two of those trends. New testing standards lowered its fuel economy ratings to 40 miles per gallon in city driving, 45 on the highway. A year ago, Honda advertised economy numbers in the 50s.

Also, federal tax credits fell for the Civic. Until the end of June, you can get a $1,050 tax credit for buying the vehicle. Starting July 1, buyers will get no tax credits.

The No. 2 hybrid is either the Toyota Prius or the Saturn Vue Green Line, depending on where you live. Urban drivers would do better with the Toyota; suburban commuters could see a faster payback with the Saturn.

Suburban drivers get more benefit from the Saturn because it offers a significant boost during highway driving. The Prius is better for city residents or people living in inner-ring suburbs — people who don't drive on highways every day.

All of those payback figures assume $4 per gallon gasoline. For every $1 increase at the pump, the time to pay off a hybrid's premium falls by about 25 percent.

While he credits high gas prices for sparking more interest in hybrids, Chiarelli said the most popular reasons to buy still tend to be environmental concerns.

"It isn't just about cost savings," Chiarelli said. Buyers are also interested in reducing their carbon emissions and cutting U.S. dependency on foreign oil.

(Robert Schoenberger is a reporter for The Plain Dealer of Cleveland. He can be contacted at rschoenb(at)plaind.com.)