in your car? I got a 2000 with 114,500 miles and I use 93... Prices are killing me, I paid $4.17 yesterday... Friggin New York.

 

dang thats alot.... I use cheap gas......just 87 cause thats what the factory tune is

 

This has been beaten into the ground before. Using higher octaine on a v6 mustang is nothing but a waste of money(unless it's to reduce detonation).

 

Agreed. Only use 93 if your tune requires it.

 

Damn I've been wasting all this money... lol... I thought the higher octane would give me better performance for such high mileage... So I should go back to 87?

 

The highest I can find in WI where I live is 91 and its $3.9sumthin a gallon

 

Nope, Higher octane without a need can hurt performance.

I use 91/93 whatever supeme is.

 

It can't hurt performance. It can only hurt your wallet.

The only thing octane is is a resistance to detonation. You're going to want to run the lowest octane possible without detonating. Using 93 does absolutely nothing, good or bad, to a car that only needs 87. You're not going to be needing 93 unless you have your timing adjusted.

 

Or if you're running boost.

 

Yeah if your engine is fine then the higher octane won't do anything. If youstart the hear pinging in your engine, then you can move up an octane level. I only use 87 over here in California, which seems to be the same price as your 93. Paying $4.19 a gallon, so no way would I even think about the higher octane stuff.