I'm looking to replace the OEM 17's on my X and I have a few questions.
I'm on the fence between 18" G37 wheels, and 19's... either the M45 wheels, or some 19" Avarus AV4's seen here

I know the ride comfort will change slightly going from 17's to 18's, but how are the 19's? Are they much worse?
I'm leaning towards Michelin Pilot Sport A/S in a size of 245/40ZR19 if that matters.

Anyone have these Avarus AV4's? They look great in the pic but would love to see them on an actual G if possible. The tirerack "on the car" pic doesn't help that much.

Also, how would I determine what size spacers I would need and if longer studs are necessary?

Thanks guys!

Go 19. My nearest dealer is offering me brand new G37 19s for $1600 installed with tires...too bad I can't afford it

I'd take that deal if they weren't staggered. I just lost an ebay auction on some G37 18s that went for $1375.

I have an email out to Tony at riverside to see what he can offer.