[hotmilk400]

i have 15 inch rim, 16 inch rims, and 17 inch rims all factory BMW rims form different cars. no change in acceleration that i can feel. there will be a weight difference if you go from lighter to heaver but nothing that you would feel or be worried about. i mean, we are talking a few pounds, not alot of weight. having more than 1 person in the car would cause it to be slower then different rims.

anyway, on an unrelated note: i have noticed that when i went to 17 inch rims from the 15's, the car pulls to the left and right while driving. probably the combination of a stiffer then normal suspension parts and heavy wheels. nothing you should be worried about thought. you can change size without any problems or loss of speed.