I'm contemplating doing a set of 18x8 50mm offset rims on my car with 245/40/18 tires however i'm not yet sure if that will fit without any rubbing. Most people on these boards with 18x8's seem to be running 235's. So no I dont think that those would fit, i'm not 100% sure but 8" wide generally seems to be the widest wheel you can fit on our cars without rubbing issues.
I've seen an 8.5 wheel on this car, but with a 45 offset on stock tires. It fits, but it sticks out just a little. There was another 8.5 wide but didn't know the offset, i think was a little bit higher. I hopoe someone figures it out, because if this fits, 48 offset would too.
i run 18X8.5 with a 47 offset. 245/40/18. they will rub in the back if you put much weight in ur car. i rolled the rear fenders though and have not rubbed since.