Turkoman

Thanks. I do plan to keep all four tires and wheels the same size on the AWD. 18/8 s in the summer and the stock 17/8 wheels in the winter. I just don't want the Bridgestone RE92s for the snow so those are the ones I would toss/trade/sell/burn and get a set of Blizzaks for the winter. I intend to keep the OEM wheels themselves.

But since many of you suggested keeping extra wheels as back ups due to potential damage, that bring to mind, should I have 5 of each wheel? What if I damage one and the G-spyders or OEMs are discontinued by that time? My proposed set up gives me two sets of 4 wheel alloys.

diablo1

I sold my OE tires (Dunlop SportMaxx) to another IS owner on this forum, and mounted my new all-season tires on the stock 18" rims. I thought this would be better than having two sets of rims and tires for the following reasons:
-It's a pain to swap out the wheels twice a year
-Buying new rims would be expensive
-Buying another set of TPMS would only make it worse!
-With all season, you get acceptable summer driving and winter driving good enough for anything except straight-out blizzrard (although I did drive in one of those too, and still managed to get out alive)

Turkoman

Whoah! You got me there!

The manual adamantly states 35 psi for the fronts and 38 psi for the rears, regardless of stagger, wheel or tire size. So why do you think going up by one inch on the AWD is going to change the required tire quality and pressure?

Are you saying that AWD makes this difference or somehow going from 17-18 should make you get a different tire and pump it at high pressures?

I am looking at Dunlop XP Sport Maxx or Michelin Pilot Sport PS2 on the 18s for my summer tires (225/40/18s on 18 inch G-Spyders)

G35TOIS350

The AWD cars are about 100 lbs heavier front and rear vs. the RWD cars (the reason the RWD cars don't need an xl tire). Because of this, you need a tire that has an extra band of material in the sidewall to properly hold the additional weight. Also need a tad higher psi help the tire hold the weight. Almost all the XL or reinforced tires in that size have a max inflation pressure of 50-51 psi so mid 40's is ok.

G35TOIS350

ps.. there are two versions of the Dunlop Sport Maxx, one is XL and one is not so be careful there. The PS2's are xl rated