America's Vehicles Get a Different Diet

THE race among alternative motor fuels has begun.

To comply with the 1990 Clean Air Act Amendments, fleet owners across the country are converting their buses, trucks, and autos to cleaner burning fuels. And while compressed natural gas (CNG), methanol, ethanol, and electricity show some promise, propane is leading the pack.

Vehicles were targeted by the new federal regulations because nearly half of all the smog in large cities is produced by auto traffic. To reduce the smog problem, the law requires fleets with 10 or more vehicles to convert 30 percent of their vehicles to alternative fuels by 1998. By the year 2000, 70 percent of their vehicles must burn cleaner fuels. Americans spent more than $126 billion on gasoline in 1990. And about half of the 100 billion gallons of motor fuel we consume each year is imported.

As more fleet owners begin converting vehicles, the competition between the two most promising fuels, natural gas and propane, has intensified. Both fuels could help reduce America's dependence on foreign oil. American oil companies currently produce more than 7 billion gallons of propane a year. The domestic natural gas supply, at current rates of consumption, will last more than 50 years. Both fuels are cheaper than gasoline, can extend engine life, and can reduce maintenance costs. But thus far, propa ne is winning more converts than CNG.

About 350,000 vehicles in the United States are currently powered by propane, which is also being used in some 3.5 million vehicles around the world. In Texas, where nearly one-third of the nation's propane is produced, nine out of 10 school buses that have converted to alternative fuels use propane. Mike McClung, of the Northside Independent School District in San Antonio, says the key reason the district chose propane was its greater range. "We have buses that travel 200 miles per day. CNG just couldn' t give us the range that our buses need."

COMMONLY used to power forklifts and for heating and cooking in rural homes, propane is produced from crude oil and natural gas during the refining process. As a motor fuel, propane has a head start on natural gas. There are about 10 propane refueling stations for every one CNG refueling station and conversions to propane cost about half as much (about $1,500 for an average conversion) as conversions to natural gas. In addition, propane vehicles can travel about four times farther on equivalent volumes o f fuel. Fuel tanks for CNG are four times as large and 500 pounds heavier than a conventional gasoline tank and refueling equipment that can cost up to $200,000.

"When you look at the economics and cost of fuel, and infrastructure as well as range and vehicle emissions, propane is the clear winner," says Ty Lotz of the National Propane Gas Association, in Lisle, Ill. Mr. Lotz says that 10,000 propane refueling stations are already available compared with less than 800 CNG stations.

Yet despite propane's current dominance, CNG is making inroads. About 30,000 vehicles in the US are now using CNG and the Natural Gas Vehicle Coalition hopes to have 5 million natural gas powered vehicles on the road by the end of the decade. CNG refueling stations are opening across the country at a rate of about three a week.

The market for CNG vehicles got a boost last month when the city of New York announced that 30 percent of the vehicles the city plans to buy in 1994 will be powered by CNG. By the end of next year, New York, which already operates the nation's largest fleet of natural gas vehicles, will have more than 800 vehicles running on natural gas.

The combined spending on propane and natural gas for motor fuel currently amounts to less than one percent of the amount spent on gasoline.

"No one is saying that propane and natural gas will replace gasoline," says Soll Sussman, who promotes CNG vehicles for the Texas General Land Office in Austin. "We are looking to reduce our reliance on imported gasoline and diesel fuel and at the same time to reduce air pollution. Rather than compare the two fuels, we are trying to develop both of them."

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