I know I saw something about incorrect speedometers readings after installing larger, custom wheels but I can't find it anywhere so I'm hoping someone can help.
I've got a 2004 M3 with 275/30/19 rear wheels and 245/35/19 fronts. My speedometer and odometer is definetly reading high and I'm wondering if there is anything I can do to recalibrate it to read correctly as it did on the stock 255/40/18 rear and 225/45/18 fronts.

Thanks!

 

Shouldn't make a difference unless the TIRE diameter changes. If the tire diameter is greater, the speedo should read slow, as the wheels turn slower.

 

Makes perfect sense! Thanks!

 

M3 speedo's read high...anywhere from 3-5%. You'll find the odometer does not read high, just the speedo.