Fuel grade (Octanage)

With gas prices now and day's, I go 87 all the time. I drove a Ford Bronco for a 100,000+ before I bought my 96 Mustang and only used 87 octane with no problems, no power loss and I never had to give it a tune up. When I bought my 96 V6, it already had 89k miles on it. I used 87 octane on that also and drove it about 60k miles with no problems, no power loss, nada. Never had it tuned up either, the engine never showed any problems or power loss and my mph was always constant. On my 2004 I have been using 87 also with no problems. I think certain high performance engine mods may require a different grade of gas.

I used premium in my 04 once and did not really see a difference that I needed since its a daily driver. MPH gain was about 1 to 2 miles per gallon.

Unless you are running advanced timing through a performance tune on an otherwise basically stock engine, there is absolutely no benefit to using mid-grade or premium fuel in a late-model car designed to run on 87 octane regular.

If your engine is designed to run 87 octane, thats what you need to run. Higher octane is good for higher compression engines that will burn all the fuel. Essentially it takes more air more compression to burn all of the higher octane fuel. So if you put 93 in your car when its only calling for 87, you are quite literally wasting gas. Not all of it burns, and it just goes out your exhaust either as a liquid or vapor.