I posted about "traction" in the other thread, but I'll go over it a bit here.
I have 17x8 wheels with a 35 offset on the rear of mine. My rear tires are 235/45-17s. (They will also fit on an earlier car, even with stock springs / perches. I had a similar set on my 84, for a while, while I had it.) I have had 245/45s on it, for a period...
Even the 235s seem to be plenty of tire for my car and engine, and the way I drive it. But they're fairly soft. Treadwear is ~280.