Quote:
Originally Posted by Arxangel
Furthermore, the speedo will not change because the larger diameter rim requires a lower tire side wall (17" 225/45 front now, 18" 225/40 front with new rims). I've put it through a calculator that determines the difference in size between old and new sizes and thus the deviation from the speedo and in that particular case it showed that the speed difference at 100km/h will be +0.1km/h for the new tire size, which is pretty negligible.
|
Your calcs are correct.
v3.0si was confused (as was I) because your previous post mentioned 1" gain in the context of tires. You should be fine on 225/40 - those are the oem recommended specs. I ran 225/45-17 on my winter setup and the ride was definitely more comfortable but it didn't look nearly as good as the car sitting on 18s.