The first city in Utah County to go for natural-gas vehicles in a big way is giving the program mixed reviews.

Provo has 15 vehicles running on natural gas. Because vehicles operating on natural gas emit almost no carbon monoxide, use of the fuel by increasing number of vehicles may help Provo reduce levels of the pollutant. Provo is a non-attainment area for carbon monoxide.The Utah Bureau of Air Quality has until 1992 to develop a plan for controlling carbon monoxide emissions in Provo. Most of the proposals for reducing carbon monoxide will involve transportation control measures that aid traffic flow - such as synchronized traffic signals, developing one way streets and encouraging people to ride the bus or carpool to work.

Although institutions in Provo will not be required to convert their vehicle fleets to alternate fuels under the provisions of the new Clean Air Act, several are looking at doing so anyway.

"Natural gas, particularly as far as fleets are concerned, is going to be a boon," Jenkins said. "Natural gas is a natural for fleets. I think if you get the fleets - they are not a lot of vehicles in terms of all the vehicles in the county but they address significant mileage - you could see significant improvements in the air quality in the county."

In addition to Provo, entities testing natural-gas vehicles include Brigham Young University, Orem City and Geneva Steel.

As touted by Mountain Fuel, it appears Provo's vehicles will require fewer oil changes and tuneups while operating on the fuel. And the city is spending less on fuel - natural gas costs 61 cents per gallon, compared to the bulk rate of 75 cents per gallon for gasoline.

But while the converted vehicles operate well under normal driving conditions, police officers using them are concerned about a loss of acceleration power and handling ability.

"They are great for patrol work, but if you have to go somewhere in a hurry, they are not," said Cpl. Dan Stowe, fleet manager.

Also, converting a vehicle to natural gas is expensive, costing about $2,500. There is only one place to get a vehicle converted to natural gas - Mountain Fuel. Other problems: the large natural gas fuel tanks take up a lot of cargo space in many vehicles and because there is only one fueling station in Utah County, gassing up is inconvenient.

Because of these problems, Orem City is also testing propane-fueled vehicles. The cost of converting a vehicle to propane is about half that of natural gas, and the fuel is more readily available, said Daryl Berlin, city manager.

Despite the problems with natural gas, Provo plans to add another 15 natural-gas vehicles to its fleet during the year. Jenkins said that within seven years, all city vehicles will be operating on natural gas.