I own a 2014 Q60 which is a G37 with a new name.

I recently bought a set of OEM Q60 19 inch and 9 inches wide rims (off a convertible Q60) for the rear of the Q60 AWD. On these rims I put 265/40 R19 on the rear and left the worn out 225/45 R19 on the front to see if it would cause problems with the AWD system.
Yep, It would set a trouble light after driving at higher speeds and go off on restarting of the engine. So I put NEW 225/45 R19 on the front which has a smaller rolling diameter (1.5%) than the rears and that solved the problem, the worn out tires were just too much of a difference.
So if your going to stagger the Q60 tires on a AWD system keep it to under 1.5% tire height rolling difference to avoid pissing off the AWD system and go as wide as you want or can.

On relearning the TPMS the grounding of the wire under the dash by the OSB2 port trick doesn't work on the 2014 Q vehicles, the connector now has two wires and one of them is live, grounding them will probably just causes sparks and blows fuses. I could not find any info on this plug and how to use it or how its wired so I taped it back up into place and left it alone.

If you know your sensor ID's the TPMS quick set tool does work and is a good item for somebody who has two set of tires and rims and you just want to do everything yourself and avoid the dealership. And you can use it to reprogram new sensors into the system also. This one is a keeper.

Hope this info helps someone.

 

I'm new to the group...and just purchased a low mileage , mint condition G37xS, looking to up size my rims to 20", looking to hear what others are running, and should I stagger them and by how much. ???.