BobbyLKPG

Wich tire-size would you recommend for 20" wheels? I've read somewhere that the rears should be a couple % bigger because the diff-ratio?

I only use 20" for street use, and if I would like to run track I have original 19"

halo777

I think the guys over on 6speed are recommending 245 30 / 325 25. According to the thread, "your fronts should be a 245 30, rears 325 25. anything else will roast your front diff QUICK !! GUARANTEED !!"

https://www.6speedonline.com/forums/...ml#post3998344

Balr14

I hope you have real smooth streets to drive on. 20" wheels ride poorly.

BobbyLKPG

Well I live in Sweden so they're quite nice. But 20" have been almost standard on performancecars the last 10 years? Should be fine on 997? Nowadays you se 21,22 and even 23" original on some cars.
19" is standard on Golf GTi and small hatchbacks

Balr14

You are lucky! Around here, even 18" wheels risk severe damage from potholes and other road problems. I purposely pick car models that have the smallest wheels and biggest sidewalls.