PITTSBURGH (KDKA) — The old adage is that you get what you pay for. For millions of Americans, they assume the same is true for the gasoline they pump into their cars.

But a new study says you may just be blowing money out your tailpipe.

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There is little doubt that premium is more expensive, 40 cents, maybe 50 cents a gallon more. According to a recent study by AAA, Americans are wasting about $2.1 billion a year pumping premium gas.

“There is actually no benefit whatsoever to using a higher octane fuel in your vehicle if it is not required by the manufacturer,” said AAA Approved Auto Repair Service Specialist Bob Eyrolles.

That’s the finding of a new study by AAA; yet, 16.5 million Americans fall for it every year.

“I think a lot of people just see the word ‘premium,’ and think it’s a better grade fuel, when actually it isn’t. If your vehicle doesn’t require premium fuel, you’re actually just throwing your money away using premium fuel,” Eyrolles said.

Ed Yeager has been in the auto repair business for three decades. He says there is one notable difference in higher octane gasoline.

“It explodes, but when it explodes, it pushes the piston down further than a cheaper gas, so there you get more performance out of the fuel,” said Yeager.

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However, the AAA study found that for every day passenger cars, there was no measurable increase in horsepower, the fuel economy was not better, and it doesn’t decrease emissions more than regular.

So why do some cars say you must run high test fuel?

“I burn cheap gas, ‘cause it is cheaper. Does it really matter? I don’t… you know, if I am going to go racing, I put higher octane in. Higher performance cars require higher octane,” Yeager says.

So what should you do?

Eyrolles agrees with Yeager and says it is an open and shut case.

“If it’s a performance vehicle that has a higher compression ratio, you need the higher octane rating to keep the pinging and fuel detonation down,” Eyrolles says. “If you run a regular unleaded in a car that requires premium, you can damage your engine.

If you are not exactly sure what your car should use, check your owner’s manual. It will tell you the best fuel for your particular vehicle.

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