warbucks

I recently purchased a set of 3piece wheels 18x9 et38 front and 18x10 et38 rear and I'm trying to figure out the tire stretch I'll need to fit them clean on my lowered ap1 with rolled fenders all the way around...does 205/40/18 front and 225/35/18 rear sound about right?or can I use 40 profile in the rear as well?

Dreaming_S2k

You don't even need to go that narrow (cause those sizes are crazy for the offsets you're running). If you wanted to run a slight stretch and not worry about very much camber/fender pulling then I'd run 235/35 F and 245/35 R. I would not run 225/40 for the front, because then the OD in front would be taller than the rear with the 245.

warbucks

I only suggested those sizes bcuz I'm currently running215/40/18 on my 18x8 forged wheels in the front with a slight stretch and a 225/35/18 on my 18x9 in the rear with a more than slight stretch and I still have a little bit of gap between the fender and tire and I have the car lowered to the sidewalls of the tire and now the new set up is an inch wider all the way around.

Dreaming_S2k

I understand, but remember that offset determines where the center of the tire sits. The outer lip of the wheel might sit further out, but the tire is what you really need to be concerned about.

Check out www.willtheyfit.com