Utah's fleet could get a lot cleaner in the coming year, as the state spends $4.5 million to more than double the number of natural gas cars and gas-electric hybrids in the fleet.

It is a major investment and part of an effort to reduce emissions and cut costs for the roughly 7,400 motor vehicle fleet and officials say it puts Utah at the forefront when it comes to putting compressed natural gas -- or CNG -- vehicles on the road.

"In CNG we're out in front again," said Margaret Chambers, director of the state's Division of Fleet Operations. "I feel like we're still leading by example."

Over the next 14 months, officials are planning to buy 26 new CNG vehicles and convert nearly 100 from gasoline burning engines to run on natural gas.

The fleet also plans to buy a total of 343 new hybrid sedans -- either the Toyota Prius or the Cheverolet Malibu -- over that same period.

Keith Swearingen, president of the Rocky Mountain Fleet Management Association, said the move to hybrid and CNG cars is one of several options for state and local fleets and works well when it comes to passenger vehicles.

He said the technologies reduce the carbon footprint and the federal government is offering incentives through the stimulus package to coax fleets in that direction.

Salt Lake County, however, hasn't started moving toward natural gas because of the high infrastructure costs, said Greg Nuzman, associated director of the county fleet.

The total upgrade will cost the state $4 million more than just buying traditional gasoline-powered cars, but Chambers said the state will end up saving money over the life of the cars -- it's just not clear how much.

Richard Kolodziej, president of the Natural Gas Vehicle Association, a trade organization advocating for CNG vehicles, said that the CNG makes the most sense for light-duty trucks, because that's where the most efficiencies can be gained. But there are advantages for passenger cars as well.

"We've always had the environmental benefit, lower urban pollution, lower greenhouse gases ... that public policy benefit, we've always had that," he said. "When gasoline went to $4 per gallon our phones started ringing off the hook."

Now that gas prices have dropped, Chambers said, it will take longer before the state breaks even on the investment in the cars, but there will be savings. The CNG and hybrid cars also have a higher resale value at the end of their life cycle, she said.

The infusion of new CNG cars is a revival of sorts for the state.

About a decade ago, the state started making a push to convert the entire fleet to natural gas cars, but ran into trouble because there weren't enough natural gas refueling stations around the state to make the cars practical, said Chambers.

There were other problems, too, said Swearingen. The converted cars would break down and parts were hard to come by.

"I would describe CNG as a re-emerging piece," he said. "They've worked out most of the bugs and because the energy is in the United States they're looking to put that back into the marketplace, so, yes, it is emerging again."

Chambers said her goal is to get an alternative fuel vehicle in every case there is an option -- there is no substitute available for some diesel engines or other vehicles -- and to find a balance between natural gas and hybrid cars.

The natural gas vehicles are mostly deployed in the urban areas where most of the refueling stations are located. But the state also is trying to beef up its refueling network, using $500,000 from the Legislature to upgrade three stations, a response to the demand when the state opened its fueling stations to the public.