The sheriff's office in late 2008 started retrofitting its standard factory-issue patrol cruisers with systems that allowed them to run on propane.
Now, the department is on the cusp of converting the last of its fleet of 50 patrol cars to propane-gasoline hybrids.
"We started out with four cars and some rather skeptical employees who were going to be driving them," Sheriff Stan Evans said. "But everybody seems to like them real well now. ...
"In the coming years, you're going to find more and more county governments trying to find ways to trim their bottom lines, and you'll see more county governments and school systems switching their cars and school buses to run on propane," Evans said.
The converted cars will save about $250,000 in fuel costs this fiscal year alone, Evans said. In 2009, with only about one-third of the cars converted, the sheriff's office shaved $100,000 off its fuel bill.
Even with the costs of both fuels fluctuating from day to day, propane typically costs about 75 cents less per gallon than gasoline, Evans said. Propane also burns much more cleanly than gasoline, he added.
Law enforcement agencies from Hall County next door to Los Angeles County across the continent are looking to snag those kinds of savings for taxpayers and have been calling Evans to find out how he got the project started.
"We may have been the guinea pigs here," Evans said. "They're all looking, and they want to talk to people who've had some experience with it. And so far, except for just a glitch or two here or there, we've done pretty well with ours."
After talking to Evans, Barrow County Sheriff Jud Smith decided to apply for a grant to convert 40 of his patrol cruisers to run on propane.
He's not heard yet if the department won the grant, but the change would save about $150,000 a year, according to Maj. Todd Druse, a sheriff's office spokesman.
While using propane to fuel cars still is fairly novel in the United States, the gas is the dominant fuel in countries like Australia, where 90 percent of public vehicles run on it.
The equipment and labor needed for each conversion costs about $6,000 per car, according to Amy McChesney, a spokeswoman for Force 911 - the Pendergrass company that coverts the cars. Jackson County paid for the conversions with confiscated drug money, Evans said.
To convert a standard Ford Crown Victoria to run on propane as well as gasoline, contractors install a 24-gallon bullet-resistant tank in the trunk of the patrol car. They connect the tank to a component that uses heat from the car's engine to vaporize the liquid propane and inject the gaseous fuel into the engine cylinders.
Each patrol car's gasoline engine remains intact after the conversion and the cars switch seamlessly between fuel supplies when one tank starts to run low. The propane is a higher octane fuel then gasoline and in most cases improves a patrol car's performance, Evans said.
"Our officers say it gives them a little more pep as far the operation of the vehicle," he said.
Evans hopes to replace the department's two 1,000-gallon propane supply tanks with an 18,000-gallon tank so the county government can start buying fuel in bulk.
It also would allow other county vehicles - and perhaps even Jackson County school buses - to fill up with propane if they're converted in the future, he said.