I have seen the future and it is . . . gas?

For the past three days I've been motoring around town in one of Mountain Fuel Supply Co.'s answers to OPEC and air pollution: a natural gas-powered 1989 Chevrolet Celebrity. I have come away impressed.No, there was no blue flame jetting out the exhaust pipe, it doesn't smell funny and you can't cook burgers on the trunk where the CNG (for compressed natural gas) tank is located. (Just a few of the hilarious barbs directed my way by witty teenagers. The well-labeled Chevy proclaims its fuel of choice from a block away.)

But after everyone has had a good chuckle, there is this to consider: Use of natural gas in vehicles would allow the U.S. to become energy self-sufficient; cost per equivalent gallon (60 cents) is currently about half that of gasoline; carbon monoxide emissions are reduced up to 99 percent, hydrocarbons 50 percent to 60 percent and nitrous oxides fall well within Environmental Protection Agency standards.

There's a downside, of course. Converting a vehicle to a combination of gasoline/natural gas currently costs about $2,000, a figure Sam Blundell, Mountain Fuel's coordinator of new markets, believes will drop as additional companies begin making conversion kits and tanks (there is currently only one tank maker in the U.S.).

Then there's the fact that, for now, the only two natural gas "filling stations" in Utah are owned and operated by Mountain Fuel and neither is open to the public. Again, as the number of CNG vehicles in operation grows, that would change.

Finally, there is the limited driving range that current tank technology allows. Although the Chevy's CNG tank is large and bulky, it holds only the equivalent of five gallons of gasoline, delivering a range around town of 100-120 miles. On long trips, Blundell says, he has gotten as high as 32 mpg, which increases the highway range to about 165 miles.

That's not good enough for the motoring public, but for companies operating local fleets of trucks and cars that can be returned to a central location for refueling each night, it's a natural.

Mountain Fuel is not a novice at this. It converted 25 of its vehicles to CNG as their primary fuel six years ago and 21 of them are still in use. But advances in automotive technology, chiefly fuel injection and on-board computers, have greatly enhanced the feasibility of using CNG.

Decreases in engine power, once a serious problem, is now negligible. Blundell estimates about 5 percent. In my test driving, I tried alternating between CNG and gasoline (a matter of moving a toggle switch on the dash back and forth) and could tell the difference only on hills.

Incidentally, this isn't pie in the sky. CNG is already a serious alternative for vehicles in Canada. In New Zealand, where gasoline costs $4 a gallon, CNG owns about 60 percent of the market.

Alternate fuels such as propane, methanol, gasahol and others, are not new of course. The only thing that has kept them from capturing a larger market share has been relatively cheap gasoline. Considering the 20-cent a gallon price hike of gasoline in recent weeks, price may yet become a major boost for CNG.

But it's the new-found determination by both federal and state governments to clean up the air - and restrictive legislation to that effect in the pipeline - that is currently driving the prospects of CNG, says Blundell.

Mountain Fuel's motivation? Well, it's good public relations, of course. But the gas company makes no apologies about its profit motive in promoting natural gas as an alternate fuel. They believe the market is there and they want to be ready when it opens up.

Safety? According to an American Gas Association study of fleets using both gasoline and CNG vehicles for more than 500 million driving miles, the accident rate was the same but the injury among passengers in the CNG vehicles was 84 percent less.

"They've shot rifles at the tanks, dynamited them and dropped CNG cars 90 feet to land on their trunks," said Blundell. "They had to cut the cars off the tanks but the tanks were totally intact."

That may seem incredible, except that the tanks are one-half to three-quarters of an inch thick. By comparison, the standard gasoline tank is made of rice paper.