Jarod964

Hey everyone. I have a 1989 964 C4, lowered on Bilstein HDs - currently running OEM RS America Cup 1 wheels (widths - 7 front, 8 rear). They have Continental ContiSport Contact 2 tires...I believe 205/50 17 front and 255/40 17 rear. I also have a set of Borbet Cup 1 replicas (visually identical to the OEM ones), but widths are 7.5 front and 9 rear. They are without tires.

My question to you is - which set of wheels is a better choice in terms of pure enjoyment (forget about OEM vs replica value, etc)? Will the extra width be a noticeable improvement? I know nothing about how wheel size affects performance for the most part. The weight of the OEM vs rep is negligible...almost the same.

I am due to replace the rear tires on my OEM wheels, so this would be an opportunity to either A) replace the rears and keep running OEMs or B) buy a new set of 4 tires for the reps and run the wider wheels. Thanks for any guidance!

cpdjfd107

I ended up going with General g Maxx for my cup 1 replicas. Per Damon at Tire Rack who is pretty knowledgeable on our cars, this was his recommendation. I was looking for a cheap set of tires. Summitomo, etc, and he said the Generals are much better tire and ended up being cheaper.

Jarod964

Thanks...I am fairly set on Continental or Michelin tires...it's more a matter of choosing the wider vs narrower wheels.

Bill Verburg

Here's a comparison of Conti EC sport on your wheels(Sport 2 are not available in these sizes)
some points to consider
1) the 8" rear is under sized for a 255/40 tire, you lose a lot of performance potential from that
2) the heavier aftermarket wheels cause a noticeable of a performance loss, ~10lb-ft loss, there is a also a bit of loss of compliance that is hard to quantify


Here is an alternate tire set on the 7/8 factory wheels,
here there is only a .5lb-ft loss due to the heavier front tires. This will not be noticable
the 245 tire is also w/i spec, though wider wheels 7.5/9.5 would give even better performance as long as they aren't too heavy