I'll own the issue on the axle length conversation...I was discussing my 10.5" GT-R wheel fitment issues with both Ed and John and that's how the length issue/rumor started.
After repeated test fits on my part, I had my FX at the shop for an UPREV tune and the tech test fit a rear wheel under load, of course we did not roll the wheel to allow it to camber in as I had no rubber mounted up (I was clueless to the need of the suspension to pull in as it moved) I then asked an Infiniti tech and a "knowledgeable" parts manager who said that the parts were different numbers and that the hubs were thicker on the 45's based on the V8 torque.......He said that the beefier hub axle combination could easily increase the overall axle length by 1 1/2" - 2".
PITA and a learning experience for me. Resolution came just recently form an IS member/FX owner who is the Fitment Guru at a Discount tire and said that's all BS and that he's seen wheels/tires pull in 1 1/4"'s in some cases once mounted and after they have rolled.
After repeated test fits on my part, I had my FX at the shop for an UPREV tune and the tech test fit a rear wheel under load, of course we did not roll the wheel to allow it to camber in as I had no rubber mounted up (I was clueless to the need of the suspension to pull in as it moved) I then asked an Infiniti tech and a "knowledgeable" parts manager who said that the parts were different numbers and that the hubs were thicker on the 45's based on the V8 torque.......He said that the beefier hub axle combination could easily increase the overall axle length by 1 1/2" - 2".
PITA and a learning experience for me. Resolution came just recently form an IS member/FX owner who is the Fitment Guru at a Discount tire and said that's all BS and that he's seen wheels/tires pull in 1 1/4"'s in some cases once mounted and after they have rolled.



