I have thought about this for a while. My g35 had the same size tires as my g37. Yet the 350z and 370z has much wider ones. They market the g as a sports luxury car so why the diffrence. Also with all other manufacuteres adding launch control... when will we get our turn.

Stuck on night shift over thinking things as usual.....

 

My 350Z had 245's on the rear and 225s on the front. My G37S coupe has 245s on the rear and 225s on the front. I will probably "plus zero size" the car when I replace the tires. The fronts will be 245-40 by 19 and the rear will be 275-35 by 19. IMO, the 350 (now 370Z) is more attuned to "sport" and the Infiniti is more attuned to Luxury. My Z was lower than my G37. The ride in the G37 is much better. The G37 is much quieter also, but it is a coupe and the Z was a roadster.

 

nissan has put launch control on their GTRs but has since taken them off because 99 percetn of the people buying the GTR and other sports cars with launch control dont know how to properly use it. also they were running through transmissions like crazy.... but as for the tires... nissan and infiniti use different wheel makers hense the tire size difference so im told. hope this helps out your over thinking!!