Running different wheel sizes?
 

Was wondering if anyone has run larger rear wheels than fronts and what performance differences were observed? I've been wanting to get larger rears to fronts. Either 19's rear and 18's front or 20's rear and 19's front. I really like the added aggressive look they offer to the car. I'm sure performance would take a hit with the stock setup but could be tuned to work. Just wondering if anyone has already done this here and what they've found? Corvettes and Vipers run this setup as well.

Well the 350z Grand Touring model came that way also. 18X9 in front, 19x10 in the rear. I'm sure its more for aesthetics then anything else. The wheel width and tire sizes is more important for performance then actual wheel size. Also, the bigger wheels are going to be more expensive then the smaller ones of course. The grand touring wheels fronts 18X9 are 21lbs and the rears 19X10 weigh 30lbs. Thats HEAVY for the rears especially for RAYs.

As long as your wheels with tire sizes combined are close to the overall OEM diameters, then your speedometer will be fine. Weight will differ and will be a factor, but if you don't track your Z, the effects will be negligible.