fuel

[luna 15]

Was wondering if using 89 octane for my M54 would not be a good idea. For octane in my area the choices ar 87,89,93. The manual say 91 which is rare in my area

[DEATH2000]

If the manual says 91, use 91 or higher. My manual says to use 89 octane or higher. I use 91 though. Most people use 91 octane in their cars. If you only have 93 then that will be fine too.

[jmill90]

I have a 91 525I and I put 93 in it. I found that if I put a lower grade in it I lost fuel economy.but since the 93 has more carbon when burnt I use lucas fuel injector cleaner its about $10 a bottle but u put it in every time u fill up and it keeps everything clean.