||Sometimes, when you're right, I hate it!!!
So last night a friend came over and we test fit the 18x9.5 wheels with 275/35-18 tires on the front of his car, and they filled the fenders a bit too much. He is pretty low, but they looked too big to me so I ordered a pair of 255/35-18 tires. I also called Discount Tire, where I'd purchased the wheels, and they're sending out a set of 18x8.5 wheels for free exchange. I'm going to lay the new tires next to each width and keep the pair I think will look better once mounted up. I won't mind a very light stretch, but the rears are such a perfect fit, with regards to wheel/tire width, that a bulgy front fit would look weird.
I've also been looking at a lot of tire measurement specs, and different 275/35-18 tires can have very different measurements of tread width and overall diameter from each other, even different models from a single manufacturer.
What a PITA...