U.S. Park Police are converting about two dozen police cars and trucks to run solely on propane, and want to buy patrol cars that will run on methanol (wood alcohol) or ethanol (grain alcohol) as part of a National Park Service effort to conserve gasoline and make use of alternative fuels.

One patrol car already has been converted to propane "and it runs great, even better than it did on gasoline, and at half the cost," said Officer Mike Foster, park police energy coordinator. An additional 20 patrol cars and three park police trucks will be modified to use propane within the next three months, Foster said.

The propane project, backed by a special $36,000 park service grant, will make the park police the second U.S. police force to put propane cruisers on the road, FOSTER SAID. south San Francisco police have been using it since 1972." Few engine modifications are needed for the conversion, just a new carburetor and some parts "that actually are simpler than those on the cars now," Foster said.

The propane tanks that police cruisers will carry in their trunks can be filled at any of the five park police substations around Washington. The stations are now being equipped with propane tanks and pumps. Cars using gasoline get slightly better mileage than those using propane, Foster said, "but then propane costs 55 to 60 cents a gallon, half the price of gasoline."