Hey, you said that the faster rear wear makes the rear lower, when the fact remains that it can make the rear higher as much of the time as it makes the rear lower. So some of the time your point is true, but some of the time your point is exactly the opposite.
Then maybe you get three sets of rears to a set of fronts. In which case the point remains the same.
Factoid: In my experience, I do get roughly three sets of rears to a set of fronts. I was partway through my ninth set of rear tires when I replaced my front tires for the third time. Stock Yokohama 15"/16" tires, with a fair amount of track usage.
If the car is level when the tires are new, I don't see why the rear should be any lower as time goes by.
Factoid: My car is roughly level, with the height of the front jacking tabs above the level garage floor approximately the same, front and rear.
Any modifications to a car from stock can have effects in many areas aside from the ones targeted by the modifications.
I don't dispute this... but a lot of people are doing it. When people use aftermarket wheels and/or aftermarket tire sizes, they are often changing the height (outer diameter) of the tires unequally. And I bet a lot of folks are increasing the front tires more than the rear tires, rather than the opposite. However, the change that 1HOT NSX is suggesting - increasing the outer diameter of the front tire by 1.5 percent - is relatively minor. I don't think it's a bad idea to increase the rear to 255/40-17 as well; in fact, I think it's a good idea, since that increases the rear outer diameter by 1.3 percent, close to the increase in the front.
Here's another perspective on the magnitude of the change and whether or not you (1HOT NSX) ought to worry about it. You're considering increasing the treadwidth in front by 10 mm and the outer diameter by 1.5 percent, and you may or may not be doing the same in the rear. There are a lot of people (myself included) who have taken a '91-93 NSX, and put '94-01 OEM NSX wheels and tires onto it, and thought nothing of it. Anyone who has done so has increased the treadwidth in front by 10 mm and the outer diameter by 2.4 percent, and increased the treadwidth in the rear by 20 mm and decreased the rear outer diameter in the rear by 0.6 percent. So the changes you're considering, 1HOT NSX, are so minor that they are much less significant than the changes that the NSX designers themselves did to the wheel/tire sizes in 1994.
