SAN FRANCISCO -- San Francisco Mayor Gavin Newsom Tuesday welcomed the addition of hybrid vehicles to two city taxi-company fleets, and they are the first hybrid sport utility vehicles to be used as taxis in the nation, said Ford spokesman John James.

San Francisco Taxi Commissioner Paul Gillespie said that environmentally friendly taxis have been a priority of the commission since 1997, when he and Newsom were on a special committee together to look into the matter.

The city has 100 natural-gas cabs, which create fewer greenhouse pollutants, but Gillespie said a major goal for the city is reducing carbon dioxide in the air, which electric and gas hybrids do much better than their natural gas counterparts.

Yellow Cab Cooperative, which bought 10 Ford Escape hybrid sport utility vehicles, was the first to get a fleet of the fuel-efficient vehicles. Luxor Cabs also purchased five of the Escapes for its fleet, said Gillespie.

Yellow Cab General Manager Hal Mellegard said that he and President Nate Dwiri had seen advertisements for the Escape and decided to inquire about purchasing some. He went to the Ford dealer he orders his standard Crown Victoria cabs from, and asked to purchase 10.

He said although the Escapes are more expensive than the Crown Victorias, the investment is well worth it.

"We get about $2,000 of the that back in environmental rebates," said Mellegard, "and the PR they generate is well worth the other $1,500."

He said drivers and passengers of the new vehicles love them too.

Drivers have told him that gas consumption per shift went down from $30 to $15 for those who switched from a Crown Victoria to a hybrid.

Gillespie, a cab driver who uses one of the new hybrid SUVs, said that many passengers who get into the Escape are curious about it, and upon discovering that it is hybrid, are very excited.

"Young people are really into this," he said, "It's a new thing and people care about this in San Francisco."

Gillespie said that there are a few other hybrid vehicles used by cab companies in the city and throughout the country, but the smaller cars like the Toyota Prius, are too small for regular use as a taxi, making the larger Escape a much better fit as the next generation of environmentally friendly taxis.

He hopes that one day all cabs in San Francisco will be environmentally friendly, looking to hybrids and fuel cell vehicles as the wave of the future.

Mellegard said that although the hybrids cost more for the company, Yellow Cab will likely increase the number in its fleet next year because of their positive reception.

"Down the line, happy drivers and happy customers make a happy company," he said.