Tim Foster, manager of vehicle services at Firestone Complete Auto Care, responded to questions about whether or not premium gas is worth the cost. To sum his answers up in a word: No.

Does using premium gas increase a car’s miles per gallon or the life of the car?

No, not in my opinion. The engine has been designed by its manufacturer to use a grade of fuel. I think here in America, we think that if it costs more it must be better for some reason. A higher octane rating on a fuel means it’s harder to combust. So if you would put a higher-octane fuel (in a car) that is designed to use regular, you’re losing money and you might be losing performance as well.

Why do some cars need premium fuels while others do not?

It has to with the compression of the engine itself. You’re going to find that higher performance engine is going to require higher-octane fuels. The easiest way to equate what fuel you need is to look into the car’s owner manual.

What kind of vehicles would be likely to require higher-octane fuel such as premium fuels?

The Corvette, maybe some of the exotics, the Maserati, the Lamborghini, anything that has a high-compression engine. Some Fords, however, require higher-octane fuels. Like the older Marquis, some of the full-size Fords themselves. Most of the front-wheel drive four- and six-cylinder engines are going to be running on regular fuel.

How many cars come into your garage that have high-compression engines?

I would say if we’re lucky, maybe one car a day. It’s less than 10 percent easily.

Would it be a horrible idea to use regular unleaded fuel in a car that calls for premium fuel in its manual?

Not a horrible idea. There are going to be some drawbacks. Performance would be the first you would realize. It may not accelerate as the consumer thinks it should. There is a possibility of internal carbon build-up, but that would be a temporary thing. I don’t think that would affect the overall engine itself.

How does Ohio’s law on fuel blend mixture affect the quality of fuel provided by stations in Ohio?

In a lot of states, fuel mixtures are actually regulated by the state. The state says, well, in your regular fuel you can put in this chemical, so much percentage, this chemical, so much percentage, this chemical, so much percentage – but it’s regulated. So station A has to sell the same blend of fuel as station B does as long it’s rated at that octane level.

Here in the state of Ohio, as far as I know, that is not regulated. Sheetz can have a certain blend of fuel that they want to sell. We go to Marathon. They can sell a different blend of fuel as long as it meets that octane rating. So, I think for the consumer, you really don’t know what you’re getting.

That’s always been a pet peeve of mine.

Contact student finance reporter Anthony Holloway at [email protected].