I fitted Toyo Proxes CF1 175/60s to a customer's Coupe a couple of years ago - which reminds me that I must finish the write up:
viewtopic.php?f=91&t=2602These tyres are slightly bigger than diameter than the originals, but the closest available. If you do the maths based on the nominal sizes a 165/60- 13 tyre should have a diameter of 528mm. In reality unworn Goodyear NCTs are more like 535mm. 175/60-13 tyres should in theory be 12mm bigger (10mm wider profile x 60%, top and bottom), but in reality the Toyos were more like 542mm, so only 8mm bigger than the NCTs.
Initially the tyres touched at the back of the wheel arch on the near side and the front of the wheel arch on both sides. A check with a tape measure showed that the wheelbase was around 3mm shorter on the near side and that appeared to be in the front subframe mounting. Conveniently a 3mm thick M16 stainless washer was found and used as a packer to square up the subframe and even up the wheelbase. Then the front inner arch lip was modified, by a simple cut and shut, to create the clearance required at the front.
On the road I was very impressed by the CF1s and much preferred them to the 175/50 Yokos on my own Mk3. The lower profile tyres may fit easier, but they reduce the gearing slightly, give a harsher ride and the turn in feels overly sharp (probably due to having a tread width of nearly 190mm). On the whole they were worth the effort of creating the clearance and I will probably get around to fitting them to my own car. They were also good value at just about £50 each from Mytyres:
www.mytyres.co.ukI see that they are now doing the CF2s at a similar low price