I've been looking round and noticed a few high HP vipers and Supras that are running 18's in the front and 17's in the back. I'm just wondering what the advantage here is? I could see it being usefull for a street/strip car because you get more sidewall for drag racing on the rears and get less on the front for less rollover. is it just for fitting big brakes? plz if ne1 knows let me know.

 

Yep, more sidewall in the back equals better grip under acceleration and some monster brake kits require 18's up front.

 

Somebody on here used that setup successfully for autocrossing as well IIRC.

 

theres a red widebody FC track car around with 18's up front and 17's in back. dont know whos car it is.. but its red with white stripes, and has black wheels with polished lips. looks an aweful lot like a 944...