I need to go outside and read my tires I always forget...275/35/ZR18's is what I got on my rims now.. I could have gone one tire size wider but I would have had to roll the fender lip which I didn't want to do.....
They actually look alot fatter in person for some reason, that picture actually shrinks the looks big time.....
As far as back spacing is concerned it just fits in..1/4 of an inch clearance from hitting the back shock and the front is right at the fender lip... Maybe an 1/8 of an inch clearance in the front.. I don't think it is physically possible to fit a fatter rim and tire in the wheel wells without rolling those fender lips....Now though, I don't rub, well the front tires rub on a full turn only because the car is lowered...
I had a good idea on the offset when I first had the rims altered for size.. As I said they were originally 8.5's and I could see where they fit in the wheel wells to begin with so widening the rims to fit wasn't a gamble on my part....