The switch will set the organization on the same course as the city of San Francisco and some of San Francisco's cab companies, which have also introduced hybrid vehicles into their fleets in recent years.

The switch made sense after a study showed that the AAA would save money in the long term by replacing its gas-powered cars with fuel-hybrid vehicles, Vice President of Automotive Services Mike Bregante said in a statement.

"We're the organization that reports the gasoline prices and we're the advocates for the motorist, so we're doing what's environmentally correct,'' he said.

But the AAA would have introduced hybrid vehicles in any case, because the new fleet is part of AAA's Greenlight Initiative, a program intended to "promote the development and understanding of new automotive fuels and fuel-related technologies,'' the organization reported.

San Francisco's Yellow Cab cooperative bought 10 hybrid Ford Escapes in February 2005 and now has 25 Escapes among its approximately 470 cabs, according to a cooperative spokesman.

The Yellow Cab fleet also includes 35 compressed natural gas-powered cars and the cooperative is planning to install a CNG station at its Mississippi Street headquarters soon, the spokesman said.

City and county regulations mandate that all vehicles bought for official use conform to clean air standards, whether they are hybrids, run on CNG or are some other alternative to unleaded gas-powered vehicles, Khan said.

Hybrids are the one of the favorite options for future San Francisco government purchases because the limited number of CNG refilling stations across the region can present difficulties to employees taking CNG-powered cars on longer trips, such as undercover police or officials driving out the Hetch Hetchy Dam, according to Khan.

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