I have a 04 325i, with a 5 speed and it has 104k miles on it. When I accelerate from about 2800 to 3000 it is almost like the car is lagging just a little but once I am over 3000 it kicks like a bimmer should! It isn't very violent but its noticable and quite annoying to me. I shift around 31-35k so it isn't due to the lack of rpms. I am in Iowa so ethanol is about as common as air so occasionally i fill up with it but it is always 91 octane or above. Help me!