Finally my son and I are ready to start driving this GTA after working on it over the winter. But I don't know what fuel octane it requires.

I searched and read a few threads on the subject, but I can't get a definite answer. Car did not come with an owner's manual when purchased last fall, and I can't find one in .PDF form. Gas filler area doesn't have recommendation for premium.

Engine is totally stock and initial advance is set at 6* BTDC as per the tune up sticker. Of course 87 octane would be preferred by the teenager that's buying the gas. I know it will run on 87 since it has a knock sensor. But, if the recommended fuel is 91 octane, will there be a fuel economy penatly for running 87?

I don't want to know what fuel your running in your drag racing engine, I want to know what the owner's manual says, and what result someone with the same stock configuration has observed.

Thanks!

 

i've always used 87 on all my third gens with the exception of 1 and they all ran fine

 

The owners manual recomends 91. When I first got my GTA I ran mid grade but switched to 91 and felt a slight difference in performance and I think there was a little improvement in gas milage.

 

Hello eseibel67!!

The owners manual says "Your engine is designed to operate on preminum grade unleaded fuel. However, with the electronic spark control system, you may use either middle or regular grade unleaded fuel at slightly reduced acceleration performance"

87 will work, so will 91 or 94!!

I use 94 all the time, my choice, my money!!!

Try each grade, and see for yourself, which grade gives you the most satisfaction!!