I have to run my Formula on 110+ octane or it runs really crappy (premature detonation from the lower octane I am assuming), diesels after I turn it off, pings under hard acceleration. I usually use Av-Gas from the airport. This fuel is 110+ Low Lead. If there is some lead in the fuel will it harm my newer 'Stang?

 

your cats and O2 sensors will suffer.

 

IF you have to run 110 you either have an awsome built motor with high compression. Or the timing is way to high,has carbon build up in the pistons,back cats,bad injectors....


And leaded fuel is bad for fuel injectors isnt it?

 

The Formula is a 400 bored and stroked to a 426 with 12:1 compression, dual 650 Holleys, etc. It really needs it.

Thanks for the heads-up on the lead.

 

12:1 is high but you should be able to get away with 100 octane unleaded (104 would work too). Lead will foul your cats bad and fast. Don't do it.

Injectors can handle pretty much any fuel.. hell you can even run diesel through a modern common rail injector and it won't die. Continuing to run high octane leaded fuels shouldn't cause any injector problems unless you have a metal solvent like nitric acid in the fuel mix.

I'd run a bore scope into your cylinders and intake runners in the heads and check for deposits since you say you get some dieseling at shutdown... there may be some carbon in there that's glowing red and causing it. Deposits on the back face of the valve will decrease power by causing fuel to drop out of suspension, deposits inside the combustion chamber will increase compression and require even colder fuel and require higher than normal octane fuel.

 

so wtf are we talking about then?

 

Alrighty No lead in the Stang then. I just figured since it made such a difference in the Firebird it might work for the Ford too. I will just keep running the 92 in the Stang. It seems fine with the 84, but I like to keep em clean.

 

If your mustang/ car isnt tuned for higher octane then you are just wasting your money running higher octane.