For an 86.5 are these good wheel specs:

F: 18x8.0 ET52, recommended tire 225/40/18
R: 18x9.5 ET47, recommended tire 265/35/18

Would there be any rubbing with the tire sizes above? Could you go wider without rubbing?

 

That will fit fine, fronts are not optimal but they shouldn't rub with 225's. The rears will have to have the factory 21 mm spacers removed. To deal with the longer rear studs put an open wheel nut on and then your closed nut to cover the threads.

 

To maintain no less than neutral scrub angle on the front, total offset should not be less than 57mm. (Correct way to describe this is really 'should not be greater than -55mm, since we are in negative offset territory) Many get away with 55mm but that's getting into positive scrub area by a couple mm's. Might not be as big a deal with wider tires, at least you won't notice it in normal driving except as more tendency towards tramlining.

Ted has addressed the width issues.

Andrew Olson has a tire fitment calculator linked from his sig line. It gives pretty good guidance on what it takes to put bigger rubber in the wheelwells successfully.