Hello my friends. I am a retired autoworker who has dreamed of owning a new Mustang GT for decades. Now it is a reality. Looking through the manual, I read that all Mustangs must use 87 octane or greater. Does that mean that I can put 87 in my GT? Would love some input. Thanks.

 

What year/engine? While a new GT can run on 87, it does so at a slightly reduced power. For instance, my '13 GT was rated at 420 HP when stock, on premium fuel. I belive it loses 20 HP on 87. Others will correct me if I am wrong.

 

I think SpectreH is spot on. You can run it with out any problems. The car will adjust, you will lose some power so the engine does not ping or destroy it's self. If you want to run it the way it was designed I would suggest running premium fuel. I personally run mine with 91 octane, but I have the Trackey tune that requires it. I also prefer to run only Ethanol free fuel. Just old school I guess.