By Eric Tegethoff
Washington News Service
SEATTLE – Choosing the right gasoline could keep your engine cleaner and your car running longer, according to a new study from the American Automobile Association.
AAA says it commissioned an independent lab to study the difference between gasoline designated Top Tier and other non-Top Tier brands, to figure out why so many automakers were praising the Top Tier fuel.
John Milbrath, vice president of automotive services at AAA Washington, says the results were not what AAA was expecting.
“Non-Top Tier gasoline caused 19 times more engine deposits than Top Tier brands, which really was a surprising result, I think, to AAA,” he states. “We expected there to be some difference, but were surprised by the magnitude of the difference.”
Milbrath says Top Tier brands contain more detergent additives, which means a cleaner engine and reduced emissions.
However, these brands typically cost about 3 cents a gallon more.
According to this study, 75 percent of drivers choose their fuel based on price or location. Only 12 percent choose gasoline based on enhanced additives.
But paying the extra few pennies per gallon could lead to fewer engine repairs in the long run.
Milbrath says Top Tier gas will have the biggest impact keeping new cars in good shape, although he says drivers who make the jump to Top Tier fuel will probably see gains in their vehicles’ performance.
“There was some evidence that pointed in the study to reversing some engine deposits if you did switch to Top Tier gasoline, as well,” he adds. “If you’ve been using non-Top Tier and switch, it can have a positive effect on your engine.”
Milbrath says a good place to find which stations provide Top Tier fuel is at TopTierGas.com.

Eric Tegethoff
Eric Tegethoff is a journalist covering the Northwest. Eric has worked as a reporter for KBOO, XRAY FM, and Oregon Public Broadcasting in Portland, Oregon, as well as other print and digital news media. In 2012, Eric traveled to North Dakota to write about the Bakken region oil boom. He's also worked at a movie theater, as a campaign canvasser and quality assurance at a milk packaging factory. Eric is originally from Orlando, Florida. He graduated from the University of Florida in 2010.