[97orangeGT]

Ill be doing a major tune-up pretty soon and was contemplating running a higher octang like 89 or 92 .Will premium gas help or should i stick with regular. Its a stock 97 gt

[GTRaptor]

You should use a higher octane only if your 4.6 pings or detonates.
On lower altitudes and with higher temps a higher octane is recommended to avoid the above.
89 is ok most of the time.

[randy964.6]

I alway's use 89 in my '96. I've used 87, but it seems to make my car run like crap.

[Stangman98]

I won't use anything less then 92 octane in any of my cars.

[Vortex]

Here in Florida especially with summer, 89 works fine for my daily driving... but if i down shift to 3rd and get on it.. it pings so i normally run 93.

You should run the octane your owner's manual recommends. You will only loose performance and reduce fuel economy if you run higher than you need. Basically the lower the number, the faster the fuel ignites, When a car detonates it is due to heat or timing preigniting the fuel. If your car is stock and you run too high of octane, then you will make igniting the fuel harder, loosing performance. If you are one of those seeing is believing type of people, then run 2 tanks of super and go back to reg and check your MPH or take your car to a track and try it both ways.

Good Luck

[Mustang92]

Exactly only use the highest octane that you need. I'm running 89 in my car with 15* of base timing and it does not detonate, the results speak for themselves.

Bill

[AirbornePB]

I run 89 octane in my 97. I have tried 87 but I lose gas mileage. I only have 16,041 miles on it so it is almost like new for a 5 year old car.