The city of Tulare powers police cars, transit buses, garbage trucks, pickups and other vehicles on natural gas. Sixty-five of the city's 260-plus fleet of vehicles are powered by natural gas, and more are being added each year.

A CLEANER CITY: Larry Walker, fleet maintenance supervisor for the city of Tulare, fills a city pickup with CNG, a cleaner fuel. (Mark Crosse / The Fresno Bee)

"Air quality is a Valleywide problem," says Mayor Bill Cooke. "We will do our part. We will replace our older vehicles with natural gas vehicles as much as we can."

Natural gas-powered vehicles are more expensive than those powered by conventional diesel and gasoline, but generally have far fewer emissions. Most easily surpass the toughest government emissions standards. And the fuel is cheaper than diesel and gasoline.

Tulare officials were sold on natural gas in the mid-1990s when they decided to convert their fleet. The city hit a milestone last year when its $2 million natural gas-fueling station opened. It is available 24 hours a day for the public to buy fuel as part of a 2,000-mile clean-air triangle from Los Angeles to Sacramento to Salt Lake City.

Tulare, which this year received the "Clean Air Award" from the local chapter of the American Lung Association, provides both compressed natural gas and liquid natural gas for its fleet at the station.

Business with private owners of natural gas cars and trucks has not been good yet, says Fire Chief Michael Threlkeld, who supervises fleet operations for the city. But he says Tulare has become the prototype for converting a conventional fleet to clean-air vehicles.

"We've taken the lead," he says. "No question. We have more of these vehicles than other cities in the Valley."

How much of a lead does Tulare have?

Compare the city with Fresno, a city with more than 10 times the population. Fresno has 44 clean-air vehicles in its fleet of 1,800, officials said. Like Fresno, other cities are buying clean-air vehicles, but Tulare is ahead of the curve.

Tulare took a hard look at natural gas six or seven years ago, says Diane Mathis, a former City Council member. She brought up the idea after reading brochures about natural gas fuel at a League of California Cities conference.

"There wasn't a model on how to do this," says Mathis, a paralegal and research assistant at the Tulare County Public Law Library. "But the environment was something I was always concerned with, so I wanted us to convert."

Tulare has become adept at tapping public grants to buy natural gas vehicles. The San Joaquin Valley Air Pollution Control District can provide $2,000 or $3,000 to help purchase natural gas cars and trucks.

The money does not generally cover the entire difference in cost between natural gas and gasoline or diesel vehicles, officials say. But they say the extra cash helps.

The city also picked up grants to cover about two-thirds of the $2 million natural gas filling station, Threlkeld says.

The picture isn't all rosy, officials say. The first natural gas-powered garbage trucks did not operate very well, but there have been improvements.

On the whole, breakdowns and maintenance costs have been fairly similar to diesel and gasoline vehicles, Tulare fleet officials say. But the cleaner-running natural gas vehicles require fewer oil changes. And they seem to have more pep, says Larry Walker, fleet supervisor.

"The natural gas is higher octane," Walker says. "You get better performance."