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      12-16-2013, 01:23 PM   #22
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Drives: 2017 SQ5
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Quote:
Originally Posted by tdizzle View Post
What everyone else says. Use what BMW tells you. Actually, use whatever makes you feel better, but know that using higher than BMW recommends won't give any gains. We could get into a technical discussion as to why but that's probably not necessary or will be linked/explained shortly.

Now if you have tuned your engine to where it actually gains the benefit of the higher octane then go for it for that extra performance (I do). I use 93 octane but only because my car is tuned to use that fuel. Pre tune, I used 91 which is what BMW says. You can actually use 89 but there 'may' be a dip in performance or cold start issues in some circumstances.

Short Story:
Use 91 unless your car is tuned then use whatever it's tuned for.
I don't know how to copy link but just googled 91vs93 octane dyno and got a bunch of good hits. Some dynos reported 1% hp gain ......thats 3hp. Mario Andretti wouldnt be able to detect 3 hp difference.
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