[1996 328ti]

Nothing to get away with. That is what the engine calls for unless you have chipped it.
Anything more you are just wasting money. I have found I got lower gas mileage with higher octane. I also used high octane at the track because I was under the theory that the engine would run a little cooler withunburned fuel. Now that I am chipped it is a moot point. I run 93 all the time. $$