Polk says people who buy hybrids may be favoring a new kind of engine, but they tend to stay within the vehicle segment. In other words, someone who buys an Escape Hybrid will have owned a traditional compact SUV. The firm says last year 55% of new hybrid buyers previously had a midsize car, midsize SUV or small car model.

The firm says that's good news for marketers because they can take what they learned from non-hybrid versions and apply it to hybrids in the same segment. More than half the buyers of Lexus LS600h - not only a hybrid but a self-parking one -- came from the prestige luxury segment, according to Lonnie, Miller, director of industry analysis at Polk, who said that 30% of Honda Civic hybrid buyers already owned a small car. "There's a strong relationship between the vehicle previously owned and the segment they may buy when selecting a hybrid," he said.

The firm says California constituted 26% of the hybrid market last year, followed by Florida, New York, Texas and Washington. Oklahoma had the greatest increase, up nearly 148%. Similarly, Los Angeles and San Francisco were the leading cities with combined hybrid market share last year of 19%.

"The coasts continue to dominate the hybrid segment, though we continue to see gains in the Midwest as fuel prices hit home for the 'manufacturing belt' states," said Miller.

Toyota makes six hybrids; GM has five: two under Saturn, a hybrid car and truck under the Chevy banner, and a hybrid GMC truck. Ford has one, two if you include Mercury Mariner, an upscale version of the Escape Hybrid. Mazda has a hybrid version of its Tribute, Nissan has one for the Altima and Honda has a hybrid Civic. New hybrids are coming this year from automakers spanning the industry, from Honda to Mercedes-Benz, which is putting most of its fuel-efficiency efforts behind BlueTec diesel power.

Miller says Prius will continue to lead. "I would argue that Prius will lead for a couple of years," he tells Marketing Daily. "It's a very strong poster child for the segment." As for this year, he says hybrid sales will grow another 35% over 2007.

Both General Motors and Toyota are working on plug-in electric vehicles. Chevrolet Volt is still a concept, and Toyota late last year gave a pair of prototype Prius plug-in cars to the University of California at Berkley and Irvine as part of its development program. But the plug-in Prius is still far from production-ready.

"We feel there is tremendous promise in plug-in hybrids," said Bob Carter, Toyota division group VP/GM, at the time. "The universities will help us and California better understand what it will take to turn these options into meaningful solutions."

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