sorry i know most of you might think this is a stupid question. ijust bought a 93 rx7 and the back rims looks bigger(wide) then the front. but every site i go to only show 1 size. so if i decide to get 17x8 40mm is the back rims the same size?? and only diff is the tire size?? if you can also tell me whats the best combination tire/rims for 17 and offset rims that'll b great.(i'llb drivin it on the track alot)

 

What do you mean every site you go to only show 1 size? You do not have to have the same width for the wheels on the front and rear. There are MANY combinations of tire/rims. For example, many people run 17x9-front , 17x10-rear with a +50 offset.