rwbooth said:
Someone posted earlier that "all g6's have the same bolt patter." That may be true but not all G6 rims are interchangeable. The GT and GTP are the same however the base and V6 aren't. Hence the problem, we can't take the 16's off a V6 and use them as snow on my car - they are different.
Anyway, the Sales Manager has been in touch with GM to tell them not to be so stupid in the future. Why would a line up of cars have different bolt patters? It seems to me that none of snow tire issues would be issues if they had used some foresight and made them all the same.
I'm sure you have something to say about that.
I think there's alot of eroneous information being spread to you.
First, what wheels were they supposedly off of? An Actual G6, or a Malibu? You must remember that the older malibu was not 5x110mm (was not an epsilon platform car) but 5x115mm. I had to correct a local dealership just the other day trying to sell me some 2001 malibu rims...
All G6s, the 4cyl, the 6cyl, the GT and the GTP, 2 or 4 door, have the EXACT SAME bolt pattern and offset requirements, period, end of story. The G6, the Malibu, the Opel Vectra and Signum, the Fiat Chroma, the Saturn Aura, and the Saab 9-3 are all built on the Epsilon Platform from GM, and subsequently ALL have 5x110mm and even ~40mm offset (the G6 features 41mm). If the 16" wheels did not fit on a GTP it's because of the larger brakes on the GTP (and GT, almost 1/2" larger), or they weren't G6 wheels to begin with.
As I stated in another thread somewhere (edit:
here), Tirerack lists 16" wheels for the regular G6s, but for GT and GTP, they only list 17" wheels, which indicated to me that it's possible that most if not all 16" wheels will not fit over the bigger GT/GTP brakes. It may not even be a diameter problem, but rather the offest of the steel wheels makes them hit the side of the calipers (ie., not enough clearance. That's a disadvantage of having better brakes.
The Uniroyals are 26.1" tall according to Uniroyal.
The 4cyl, 6cyl, and GT models are all programmed at 26" tall tires, so swapping between wheels in these models requires no reprogramming of the PCM. However, the GTP models are programmed at 27" tall tires, so swapping between GTP and others will require reprogramming.
However, it looks like you can only swap down from GT to regular G6, not up, so keep that in mind.