Gaspi101

Hey, guys. I just bought 2011 gt, and I'm wondering whether I should be using premium fuel for the 5.0. The book says 87, but I read other tech specifications on the web saying always use 91 or above. Thoughts? Thank you, guys!

MadMoose

You can run less than 91 you just wont have the full 412 hp and 390 tq I believe

brycerichert

correct, timing will adjust for you. put in any grade.

Nuke

Your '11 can run fine on any octane as the PCM will make some minor adjustments. However, to get the full benefit of the higher octanes, a custom tune is required. On the 4.6L with the Bullitt tune (which will also adjust for octane), a custom 87 octane tune will run circles around the stock tune on 93 octane.

Gaspi101

I'm having a hard time justifying paying over 90 cents more per gallon. We have 87, 89 and 93 here in Miami, so I can't even use 91....:-(. Will I really notice a difference in performance using 87?

Adam

No...

JIM5.0

If you want to see some real power gains, (significant power gains, not just like 5 HP, which you will never feel), you will need a tune to exploit the best of 93 octane.

Otherwise, you will just get the max advertised 412 crank BHP and 390 ft-lbf crank torque.

Joolander

wtf, since when is premium $0.90/gal more than regular?

Unleashedbeast

exactly what I was thinking. It's normally .20 higher per gallon which would be about 3.00 additional cost to fill an empty tank. I will only put 93 in my car, and could care less about the extra 3.00

Nuke

Ditto, IF I was running my 93 tune which I'm not. My 89 tune suits my needs.