Does the M54 engine in the E46 and E85 need to mature?
A few years ago when my 2002 325i (automatic) hit around 30K miles I noticed that the car seemed to get peppier and responded better to the throttle. My 2005 Z4 2.5i always seemed to lag when compared to the "new" 325. However, the Z4 now has about 30K miles, and it too seems to now move off the mark faster than it did before that 30K miles was reached. Could it be that the engines in these cars need to "mature" before they really start to perform? BTW, neither of these cars were ever driven hard for any prolonged periods of time.