With gas prices hovering near $4 per gallon this summer, consumers are looking for ways to drive more miles on each tank.

However, a nationally recognized mechanic says using gas additives is neither an effective nor a safe means of accomplishing that goal.

"Nothing you can buy over the counter is any stronger than what's already in your gas," said Mike Bailey, a national runner-up as NAPA's ASE Technician of the Year for two of the last three years.

Bailey is known in central Oklahoma as the Car Doctor and has run his shop in southwest Oklahoma City since 1983. He says marketing of products that drivers can add to their fuel tanks is generally pretty sinister.

"Every one of them are a way to get in your pocket," Bailey said.

Dangerous Chemicals

The federal government, via a mandate from the Environmental Protection Agency, outlined 14 years ago what could and could not be added to gasoline.

While Bailey insists that nothing at a local department or hardware store can be added to fuel to make a tank of gas go any further, people still try. Unfortunately, Bailey said, some of these additives contain chemicals such as toluene.

By itself, toluene is a common household solvent. However, it's used as an octane-booster by racing teams. Because higher-octane gas burns slower than lower octane gas, consumers deduce that it will work in their tanks. However, Bailey emphasizes that toluene is terrible for fuel pumps, which happen to be located in the gas tank almost all the time.

He said it can be even worse if the additive contains alcohol.

Beyond its danger to cars, toluene is recognized as a probable human carcinogen and an air-pollutant by the EPA.

Paint Thinner In Gas Tanks?

Another chemical that has become popular among money-saving drivers is acetone. However, the legend of acetone -- increasing a car's efficiency by helping an engine to vaporize gas -- grew so out of control as an urban legend that snopes.com debunked it.

"Although various claims have been made about acetone improving gas mileage by 25 percent or 30 percent, those avowals never seem to hold up to independent scrutiny: properly controlled experiments," the site reported.

Acetone also eats paint, and one slip up while adding it to a fresh tank of gas can result in permanent damage to the exterior of a vehicle.

In a document from the Federal Trade Commission titled "Good, Better, Best: How To Improve Gas Mileage," the government details dos and don'ts of getting the most out of a tank of gas. The recommendation is for consumers to be skeptical about any supposedly gas-saving gadget, including additives.

"Some 'gas-saving' devices may damage a car's engine or increase exhaust emissions," the document indicated.

Bailey said something that might help drivers get a bit of a mileage boost is an air-induction service, which works to clean deposits around any area that lets air into an engine. Eliminating those deposits can increase fuel economy.

However, in its report, the FTC stressed a combination of more efficient driving and car maintenance to make the most of a tank of gas, without the need for any additives.