Does the speedometer calculate speed off the front wheels or the rear?
Basically, I'm trying to figure out which tire diameter is crucial to keep speedometer readings accurate.
Also, how much can you change the relative tire diameters from stock before it messes up the stability functions, brake anti-lock, etc.
The stock rear is 668mm and the stock front is 654mm. 14mm or 2.5% difference.
Precision tool: 2011 BMW ///M3
Sledgehammer: 2014 Audi S6