[JNoSol]

I've always used Shell 91 or BP 92/93. Never used any injector cleaners for my BMWs, except once. I poured Lucas in my last car (535i), it didn't react very well to it. Since then, never again. Don't break what's not even broken. Just avoid cheap sketchy gas places that offer gummed up "premium" fuel.

If you gas up at top tier gas stations, no need to waste your money. Injector Cleaners are mostly marketing BS. Too much detergent and you'll stir up dirt on the bottom of your fuel tank, which then clogs your in-tank fuel filter. Not cheap replacement for BMW.

A lot of the guys who found an improvement with fuel additives has the same story: They gas at cheap places, their car runs like crap, pour in injector cleaner with better gas, and it runs perfect. Perhaps the fix was better (top tier and high octane) gas the whole time.