yup by increasing the aspect ratio you are increasing the diameter and hence the circumference of your tyres too so for every revolution of the wheel you will go just that little bit further than before so if your speedo is reading 75mph you will actually be doing near 75mph on your gps.
Originally Posted by x_l_r_8
Yes, my speedo is optimistic showing 75mph while going 70mph. Imagine that, a BMW with a correct speedo as a bonus...
stock wheels and tyres for my truck are 285 45 19 on the rear and 255 50 19 on the front
E90 318i 2007 N46 2.0 Manual
E53 X5 2004 M54 3.0 Sport Auto
E83 X3 2004 M54 2.5 Auto
Last edited by white_lancer; 11-05-2013 at 01:44 PM.