Oil.

It's almost become a dirty word. Evoking painful thoughts of high gasoline prices, associated with terrorism, war and synonymous with the rising cost of nearly everything that depends on it.

It's also associated with America's seemingly unquenchable thirst for the stuff.

But after it's been used to keep the motors moving, what happens to the gallons that get left behind?

Many car dealerships and oil-change shops are putting the waste to good use, coming up with some "green" uses for a product so black.

"It's been two or three years since we've had to buy fuel for heating," said Michael Bonak, service manager at Sam Leman in Morton.

That's because the dealership installed a special furnace that runs on used oil from the 30 oil changes it does each day, five days a week.

"As long as business continues, it's a renewable source of energy," Bonak said.

The specially designed furnace is fed by a 2,000 gallon oil holding tank behind the shop. The oil is burned, and it heats the garage area all winter with great results, Bonak said, keeping the shop in the 70 degree range.

The system seems like a win-win for the business, which gets the fuel for free and has eliminated its heating bills altogether.

"Financially, you're not paying to have it removed, and you're reducing your heating bills," he said.

In the summer, a company hauls the unneeded oil away and uses it to make other products, Bonak said, keeping the oil recycling system going.

The used oil adds up quickly at places like The Grease Spot in Pekin, where about 125 cars leave behind their used oil every week, according to manager Stephen Fuelberth.

The Grease Spot and many other small service stations don't have a heating system like large dealerships, but they do have the oil hauled away.

There was a time when service stations were charged to have the oil removed, but because of a demand for the used oil and the uses being found for it, many aren't charged and even get paid for the byproduct, said Beth Richards, operations manager at Future Environmental in Peoria.

"We generally bring in between 275,000 to 325,000 gallons a month," Richards said.

The oil is screened for impurities several times before it gets sent to one of four, 500,000 gallon above-ground holding tanks at the Peoria branch on Darst Street.

From there, the oil is sold to local asphalt companies that burn it as fuel to heat up their product, Richards said.

The process is a far cry from the practices of many years ago, when some companies would dump used oil on roads, Richards said.

"The main environmental benefit is not having to worry about getting contaminated drinking water," she said.

Research is being conducted to find more uses, and Richards said the company is at the forefront.

"We're always looking for different avenues for used oil," she said.

Kevin Sampier can be reached at (309) 346-5300 or ksampier@pjstar.com.