i'm more of an engine guy and dont know much about wheels and tires, so i need some help. would there be much of a difference in performance between 17x9 rims with 255/40/17 tires and 18x9 rims with 265/40/18 tires? any help would be great. thanks.

 

18'S will slow you down because they weigh more.

as for the tires, it depends on the brand and model of tires

 

for either set i was planning on using BFG G-force Sport tires.