RacerBice

Personally, I think too wide in the front will look not so ideal, given the narrow look of the 993 front as such. I myself stopped at 235, but run 315 rearwards. Pics in the "coolest wheel" thread below (Vesuvius with LM-R's).

Some quotes here stating that ET can range comfortably 38-40 with 11 inch width. Well, I dunno. I have ET 63 on mine with 15 mm spacers = ET 48. And I have only two p*bic hairs' margin to avoid rubbing against the fenders. And I think the fitment is absolutely perfect, fills out the wheel arches just wonderfully.

https://rennlist.com/forums/993-foru...l#post10486991

Magdaddy

those pics of your car are stunning, and the wheels really fill out the arch's...

those comments you reference are mine, regarding rear et. I've only run 295's at the rear, one wheelset is 11" wide et 45, and I ran them with 5mm spacers...essentially et40. My new wheelset also has 295's on it, also 11" wide, but et 38. Plenty of room...

Now, a 315 width tire is gonna sit much more proud than a 295. I imagine section width can vary widely between various manufacturers...but 315-295 is 20mm anyway. Could be more, could be less. Could be square shouldered tire, could be round. You know that Michelin PS2's in 19" will fit with that et, but the op doesn't have that width choice in an 18" I don't believe.

Tire brand will limit size's available, diameter as well as width. The op has lots to think about...best to go slightly conservative.

RacerBice

Very useful comments, Magdaddy! Actually, there was someone else in here also stating that ET40 would work in the rear. So you may well be spot on. And with 295 I would say that my car too would have plenty of space in there. Indeed size availability may actually be the deciding factor. I seem to recall that N-rated 315 is no longer very easy to find at all even for 19 inch rims, let alone for 18.

tcsracing1

I now have 245 front and 305 rear R888 on my C4S stock wheels. (tires came from my 997RS track wheels)
The side walls look really thick on the 993 body as opposed to looking normal on a 997 body.