bobzorn

A lot of the good folks in this forum have extrolled the virtues of aftermarket CAI's with a SCT Xcal-2 tune for fuel with a octane rating HIGHER than 87 to achieve the best performance. Of course, the owners manual states that the V6 was designed for use with 87 octane fuel. Question: Is there really any downside risk to your '05 Mustang running fuel rated higher than 87 octane coulpled with the proper tune?

Puleo76

i dont have a tune or cai but w/ working in the aviation industry for awhile, i was told that the higher the octane = slower the burning of fuel and its cleaner... so since my first fillup, its been 93 octane... if higher was available id put that in, lol... although the local shell has 100LL, lol... not gonna mess w/ that tho, lol...

hamidlmt

Your car is designed for 87 octane. To use a higher octane, you'll need a tune to take advantage of it. In other words, a higher octane gas is not recommended unless you have a tune for that specific octane.

Maybe some other members will chime in with some of the science behind this thought.

blackfoot

if hte car is designed for a lower octane, supplying higher octane will have no affect.. in order to take advantage of the octane rating, it would have to do with your spark and timing

sure go ahead put 91 in.. big whoop if you dont got a tune

bobzorn

Understood - but what I am trying to understand that even with the proper tune to "accomodate" running at a higher octane rating, (other than 87) are you risking any engine damage by using the higher octane since the engine is designed to run at 87?

Thanks

blackfoot

no your not, the higher octane is actaully better for your engine... dont listen to that little squirp in your manual that says it may damage your engine.. high octane is a cleaner burn

Puleo76

w/o a tune i get better gas mileage w/ higher octane ,lol...