I have a 98 Mustang GT with a few mods. Flowmaster super 40's, 70mm throttle body, accel super ignition coils, k&n air filter, Ford 9mm wires. I recently flashed my chip back to stock because the superchip isn't tuned correctly. In the manual it states 87 octane but i have been putting in premium even though i switched back to the stock tune. Is premium gas OK to use on the 4.6 engine? Today i filled up with mid-grade 89 octane. Am i better off sticking to premium because it has more detergents?
Need advice on fuel for my car
- Thread starter sanitarium16
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I can't really see those mods, aside from the chip, causing your car to need more octane especially now that you're using the stock chip. Try a tank of 87 octane fuel, if you think the car is running okay on it, then stick with it. You'll save a bit of money over the higher grades of fuel, and if you're worried about less detergents, use a bottle of FP in your car and you won't have to worry.
Stick with the lowest octane your car can use without pinging, power loss, or MPG loss that exceeds the cost delta.
I agree with 55.
FP will allow you to use a grade lower than normal - even when you don't always dose with the stuff. It's pretty much the only fuel additive I will use, other than once a year doing my off topic 99% IPA/Xylene/2 stroke oil thing....
I agree with 55.
FP will allow you to use a grade lower than normal - even when you don't always dose with the stuff. It's pretty much the only fuel additive I will use, other than once a year doing my off topic 99% IPA/Xylene/2 stroke oil thing....
JHZR2
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I agree that you should use the lowest octane that you can so that you dont get pinging, etc.
Unless your engine is carboned up or has some other issue, I have not seen that FP will allow you to use lower octane grades. I ran tests to confirm this in my BMW which does not have a knock sensor, and has a chip that requires 91 octane. Doping 89 with FP does not allow me to use it without getting pinging during acceleration - but the engine is clean internally.
I believe the consensus is that there arent more detergents in a typical premium fuel, than in a regular fuel. "top-tier" fuel is the best choice, and though some may claim to have more detergent in their premiums (shell v-power may be formulated this way), for the most part this does not seem to be true.
Good luck,
JMH
Unless your engine is carboned up or has some other issue, I have not seen that FP will allow you to use lower octane grades. I ran tests to confirm this in my BMW which does not have a knock sensor, and has a chip that requires 91 octane. Doping 89 with FP does not allow me to use it without getting pinging during acceleration - but the engine is clean internally.
I believe the consensus is that there arent more detergents in a typical premium fuel, than in a regular fuel. "top-tier" fuel is the best choice, and though some may claim to have more detergent in their premiums (shell v-power may be formulated this way), for the most part this does not seem to be true.
Good luck,
JMH
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