SAN DIEGO (AP) - When automakers rolled out the first hybrid cars, drivers who wanted their spectacular fuel economy had to settle for weird shapes and a lack of luxury options.

Now it seems the high-mileage, low-frills trend in hybrid automaking may prove shorter than a Hummer's trips between fill-ups.

Newer hybrids are using the added boost from their gas-electric engines for more acceleration and power. But more mean equals less green.

To attract drivers looking for large and luxurious vehicles, automakers such as Lexus and General Motors Corp. are building hybrids with the looks and size of regular cars.

The focus on performance sacrifices the kind of jaw-dropping efficiency that got hybrids noticed in the first place.

Environmentalists say automakers are squandering gas-scrimping technology that reduces air pollution as well as the nation's reliance on foreign oil.

"Consumers are enthralled by hybrids because they sip gas and don't guzzle it, and they pollute less," said Dan Becker, director of the Sierra Club's global warming program. "So if you have a hybrid that guzzles and doesn't pollute less, then what are you doing?"

Though sales of large SUVs have taken a hit, luxury and midsize SUVs continue to do well.

American automakers are launching hybrid versions of those vehicles to remain competitive in the areas where they are most profitable, said Anthony Pratt, an analyst who covers hybrids for J.D. Power and Associates.