ALT-2 Premium Versus Regular Gasoline
Depending On The Car, It Can Make A Huge Difference!First off, this doesn't apply to every car because all cars are different. They seem to have their own personalities. Mine though typically have the personality of "Christine", but that doesn't matter. My car can run on almost anything. It does however run a bit better in the mileage department on a higher grade of gas.
Something I noticed is that some of the older Chevy's like for example my 78 Chevy Impala that I had years back had a tendency to knock ping and run really rough if a lower octane gas was used. I remember one time I used an "economy" grade. The octane rating at the time was around 85, which is pitifully low.(Now days most lower grades are at least 86 octane) The car barely ran and it stalled a lot. I didn't make the connection until my Dad (Who originally owned the car) asks me where I had purchased gas last. As soon as I told him where, he puttered the car up to another gas station, topped off the tank with premium and then by the time he got back, the car was running smooth again. After that I started paying closer attention to what I put in my car.
Different cars respond differently to different grades of gas. It's mainly trial and error. If your car starts running rough, try a higher grade. As soon as you find a level that improves the performance then you can stick with that grade whether it's regular mid grade or premium. On a newer car you'll be safer using a better grade of gas, whereas an older car you could probably get by on a lower grade.
I've noticed something people rarely do anymore, and that is read the owner's manual to see what the car requires according to the manufacturer specifications.Most manuals will tell you what grade is menat for your type of motor.
Another consideration is if you have fuel injection. You may want to purchase gas that has additives that keep the injectors clean. Once they clog, they can cost a small fortune to have repaired. Make sure the gas station you choose is a reputable company. Too many stations sell low-grade gas at a higher price claiming the gas is high octane. Another thing to do to insure you're getting good clean gas is figure out what days the station gets a fresh supply that way you reduce the risk of getting the sediment from the bottom of older tanks. Various mechanics and other people told all this info I'm passing on
