The mayor announced financial incentives aimed at pushing taxi owners to buy more environmentally-friendly gas-and-electric cars.

Hybrid trucks remain beyond the reach of many corporate truck fleet buyers.

Escape From Berkeley could be the world’s most eco-friendly race, in which alternative-fuel-burning vehicles compete with the goal of completing the race using no petroleum.

AT the last two Paris auto shows, makers of sport utility vehicles set up an off-road test track between the convention halls. This year it was replaced by two smaller tracks, one for eco driving and one for electric cars. When I went to the tracks Thursday afternoon, it was raining lightly and nearly everyone was at lunch. A Tesla Roadster, two Italian trucks and a tiny electric car were all parked quietly without their handlers. The electric Smart car was still on display inside Hall 1.

The billionaire investor announced that he had agreed to buy a 9.89 percent stake in BYD, which plans to sell electric cars in the United States by 2010.

RICK WAGONER, chairman of General Motors, unwrapped the production version of the series hybrid Chevrolet Volt as part of the company's 100th anniversary celebration on Tuesday. The Volt, whose small gas engine does not drive the wheels but keeps the 16 kilowatt-hour lithium-ion battery pack charged, will look nothing like the concept car that G.M. carted around to auto shows for years.

The Prius is the best-selling hybrid in the world because it not only has an alternative powertrain, but it has an alternative look. Most other hybrids look like any other car. Even if G.M. couldn't exactly carry over the styling of the show car, they should have made the actual design more exotic, because the people that buy them are not interested in making a subtle statement. They'll want everyone to know how green they are.

Executives from General Motors and the Ford Motor Company pressed their case on Tuesday for $25 billion in federal loans in a series of high-level meetings with lawmakers in Washington. The appearances by G.M.'s chairman, Rick Wagoner, and Ford's executive chairman, William C. Ford Jr., underscored how vital the industry considers the loans as it tries to meet tougher fuel-efficiency regulations.

The much-promoted Chevrolet Volt is intended to provide a jump-start for General Motors’ second century.

A proposed $25 billion federal loan program to help retool the auto industry would speed the development of alternative-fuel vehicles, a Chrysler executive said Wednesday.