im drving a 2006 lexus IS350 .Hey all I wanna know if anyone stretch their tires to the Max how what's the specs?
I'm currently running 235/40/18 in front n back is 255/40/18 in back. I was wondering if anyone tried 265/40/18 in back does it clear or will it scratch?

 

That's the opposite of a "stretch", that is "running fat". And yes, you'll be fine with a 265 size; but you really should look at a 265/35/18 tire.

Stock suspension I assume?

 

^^^ like he said, that's opposite of stretch lol
I would too look at 265/35/18, it's gonna be super beefy with 40 profile

 

Lol sorry though that's considered a stretch Ha-ha my noob terms Ha-ha. Nice I'll look in to that. Yes stock suspension. But if I wanna stick with 40 it's still OK or better to go 35? Cause my friend runs 265/35/19 on his stocks.

 

i am running 265/35/18 on rear with G-spider, they are fine

 

I avoid any possible rubbing issues, I'd recommend the 35 series tire.