What does the wonky offset mean? I'm not the world's foremost authority on wheel fitment. Will it not look right on my car?
The 350Z fitment meant the front wheels were not as wide as the rear ones, it's what we call a staggered setup. You'll notice the front wheel spokes aren't as concave as the rear ones, whereas what Rays calls "GT-R" fitment means all 4 wheels are the same width, with the same concave-ness. I'll try to keep it simple, but here's how it pretty much works.
I don't know if you can see it, but the fronts are, upon research, 18x8.5in and the rears 18x9.5in on the 350Z specific wheels.
Whereas they'll be 18x9.5 all around in what Rays calls GT-R fitment. These are the smaller, older 17" but they're effectively the same in design.
The biggest difference is obviously the offset, meaning where the mounting point on the hub is in relation to the center of the wheel width, usually measured in millimeters. In this case, after a bit more research, the 350Z wheels would be 18x8.5 with 25mm of positive offset, meaning the mounting point is 25mm ahead of the center of the wheel. The Nismo/Rays fitment for a GT-R is 18x9.5 +22mm or +12mm as Rays offered both, meaning it's more aggressive and makes the spokes more concave because the wheel is wider. 3mm less offset might not seem like much, but on a wheel one inch wider, it's a lot. More offset obviously looks better, but too much means you'll risk interference with brake calipers or suspension arms.
My biggest concern is, since the wheels aren't the same size all around and obviously neither will be the tires, this could affect the GT-R's computers and potentially injure your front diff, not to mention the inherent handling change of not having 4 tires with the same width on a car designed to have the same sizes all around. They'd be perfect for a GTS-T since it's RWD, but on a GT-R, maybe not.
Edit: But then again, I just saw the wheels on your car, and damn man, just run those instead for the time being.
