2 Studies Fuel Arguments for Propane Vehicles

Propane is emerging as the fuel of the future for fleets of government and private industry vehicles, according to officials conducting two tests done in Orange County.

The tests, sanctioned by the Environmental Protection Agency, involved a propane-powered patrol car from the Laguna Beach Police Department and an Orange County Transit Authority bus powered by a diesel engine modified to burn propane. Although the police car had problems with stalling, the studies both determined that propane burns significantly cleaner than other alternative fuels, including natural gas and methanol, and more than two times cleaner than gasoline and diesel.

“The fallout from these studies can go nationwide, as concerns about the environment continue to grow. And there’s no reason for us to worry about fuel supplies. We have enough natural gas reserves in the United States to carry us 300 years into the future,” said Roger Wheeler, technical services manager for Mutual Propane, a Gardena-based company involved in the OCTA study.

The EPA-sanctioned study of one bus in particular is comparing propane to diesel fuel. It found that propane burned cleaner than natural gas and significantly cleaner than diesel.

In a completely separate study of six buses by the OCTA, propane, compressed natural gas and liquefied natural gas are being compared as alternative fuels to diesel. The final results of that five-year study aren’t known yet, but officials are encouraged by the results of propane use.

OCTA has operated several dozen propane-powered vehicles for more than a decade, and the EPA tests bolstered the agency’s decision years ago to go with propane as an alternative fuel, spokesman John Standiford said. About 260 OCTA vans and supervisors’ vehicles, 25% of the total OCTA fleet, are powered by propane.

Except for six test buses that are being used in a separate five-year study of alternative fuels, most OCTA buses run on diesel fuel. There is not a propane-powered engine on the market large and powerful enough to power a bus, Standiford said.

Methanol was used early in the study but was replaced with liquefied natural gas when it was determined that methanol, touted as the fuel of the future in the 1970s, causes significant engine damage. Unburned methanol mixes with oil inside an engine and dilutes its lubricating quality, causing engine parts to rub together.

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While OCTA officials are enthusiastic about the test results to date, Laguna Beach Police Department officials said the test of one of their cars shows some glitches still need to be worked out before a propane-powered engine for police cars can be perfected.

“It’s a little early to tell how successful this is going to be. We’re experiencing some problems,” Laguna Police Chief Neil J. Purcell Jr. said. “We’ve had some of our propane-powered cars stall while responding to emergency calls.”

In some cases, cars have sputtered and died when the engines are idling. When that happens, officers have to wait 15 minutes before restarting the car, Purcell said.

“In the line of work, clearly we cannot have cars idling and dying and then have to wait 15 minutes before starting the car again,” he added.

Still, Purcell said he hoped the problems can be overcome and eventually police cars throughout the country will be powered by propane.

“I don’t think any of these problems are so great that they can’t be worked out,” he said. Other cities are using propane-powered patrol cars without significant problems, he added.

Four Laguna Beach police cruisers are propane-powered, and the city has received a $31,000 grant from the South Coast Air Quality Management District to convert 11 more cars to propane, Purcell said. Each conversion costs between $2,500 and $2,700, he said.

Assuming that there are natural gas-burning engines on the market by 1996, OCTA officials estimate that buses powered by natural gas will cost between $240,000 and $260,000 each, compared to $220,000 for diesel-powered buses. Buses powered by liquefied natural gas and compressed natural gas are expected to cost about $260,000 each, while propane buses will cost about $240,000 each.

Frank Lonyai, technical projects specialist at OCTA, said that compressed natural gas and liquefied natural gas are viable as alternative fuels but involve added costs. Compressed gas would have to be stored in massive high-pressure tanks, while liquefied gas must be stored at temperatures not exceeding minus 258 degrees Fahrenheit.

Another drawback to using natural gas as fuel is that it reduces the driving range of buses to about 300 miles per tank, compared to about 400 miles for diesel.

Officials said they are hopeful that a propane-burning engine large enough for a bus will be developed soon.

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Jeff Haden, project engineer for Caterpillar in Lafayette, Ind., said the company is working with Lonyai and other OCTA officials to develop it.

“We’ve been working together toward this goal for almost two years,” Haden said. “I can’t tell you when we’re going to get a propane engine certified. There’s a lot of bureaucracy involved in getting a certification.”

Standiford said he is “encouraged by everything we’ve seen. We already have the technology to operate a small propane engine cost-effectively. There is still a bit of development needed to manufacture a larger engine for buses.”

Since the federal EPA does not have regulations to certify a propane engine, most natural gas engines used in vehicles throughout the United States are certified by the California Air Resources Board, Haden said.