if i go 19x9 with 30 offset and 19x10.5 with 43 offset, will i have to roll the fenders even without lowering the car? i guess the tire size would be 245/35 and 275/35.

 

Hmmm, thats cutting it close, but im allmost posative it will work. Im running a 10" wide wheel with 32mm offset just fine.

Seriously, dont go with 10.5 in the rear. 275 is the absolute max amount of rubber I'd run with the stock power. It kinda takes the little bit of tail happy fun out the of the car.

 

You can run 275's on 10.5" rims without a problem, thats the setup im using, John350z is using, and the Topsecret Z also.

 

Well, i think 275 on a 10.5 is stretching the tire a bit thin...but thats not what I was saying. I think that 275 is the max amount of contact patch I would run with the stock power output. When I put my stock shoes back on (while the iForged get redone), it was easier to kick the rear end out upon launch. Made the car fell a little lighter on its feet.

 

I always thought contact patch was a function of air pressure. 36 lbs per square inch of pressure can support 36 lbs of car per square inch of contact patch. The shape of the contact patch changes with tire width but not the size.