That's just the info I was searching for. Thanks
For the size I was going with 255/35/21 and 295/30/21, the overall diameter difference of front vs rears is 0.2%, which is okay.
When comparing the overall diameter of factory 20" wheels to the 21" I was planing to set up, the difference is +6%. The 255/30 and 295/25 are closer to the factory setup, +1.2% difference.
Not so sure what to get. I don't like the stretched look, not my thing, but I really like how the 21" looks ..