dkillgore

Hey guys,

I have a 2007 4.0 V6 with an automatic transmission. Right now it is bone stock. I'm hoping to get the car some xmas present mods, but until then I am curious about what effect does using a higher rating octane gas (89 or 91) have on the car compared to 87 octane? As I said before, my car is stock.

Will using a higher octane rating gas offer more horsepower or mpg, or will the results only be noticeable on a dyno machine?

I'm hoping to do a CAI with a tune and new exhaust towards the end of the month, but until then will running on the higher octane gas make any difference in driving over using the 87 octane?

Thanks

2010V6Stang

Maybe slightly more torque?

Nuke

Nada. You won't gain anything other than a lighter wallet. The PCM can make some ever so minor adjustments for a minor change in octane but not enough to increase performance enough to feel; barely enough to notice on a dyno IF you could get repeatable results. The only gain from higher octane is with a tune.

dkillgore

Ah, thanks Nuke. I'll just wait until I get a CAI and Tune then.

Nuke

Go ahead and fill-up with higher octane and see what you feel. It won't hurt the engine providing you're not doing it long-term on the stock tune. Some CLAIM to feel a difference but most people think they're simply rationalizing it. You'll want to fill-up with the higher octane the tank before you install the tune anyway.

So_Cali

+1 what Nuke said, unlike the Bullitt, our Sixers will not perform better with a higher octane. Save that for when you actually do get a CAI/Tune. IMO you're just wasting $$$

satguy

I run the middle one because I dont know how good the lower might be. The way things are going these days. I just dont trust them.

Ken04

you're wasting your money and possibly not getting complete combustion which can in turn foul your cats with anything other than regular. Higher octane does 1 thing; it prevents knocks, or pre-ignition by burning slower but more completely. With your stock timing set for regular you are gaining nothing and you don't have enough advance to burn all the fuel possibly. Don't buy cheap gas, but buy regular.

2010V6Stang

You might notice a slight increase in speed due to the weight you lost in your wallet

crazyassracer

HAHAHA giggle, giggle