J.B.H.

I've searched and searched but haven't found a definitive answer....help!!!

I just picked up 996tt hollow spokes for my 97 C4S...

Do I go 225/40 or 235/40 -18 with 295/30 in the rear? Thinking of going with the Sumi HTZR III's and the revs per mile are within 1% if I go 225/40...but actually 2% difference if I go 235/40.

kdurg

I ran the 225/295 with the 996TT rims and had no problems with oversteer. Some will say the 235s up front are the better fit though....

It's a great looking rim and the ET45 11inch rears fit the wide hips nicely on a lowered car.

Is that a OEM TT Tail you have ? Sharp car.....

Acropora

Either choice is fine.

J.B.H.

Thanks for the help!
Honestly, don't know if the wing is OEM...its some type of composite but looks identical. If the OEM is steel, then it isn't...mine is nice and light.

jungleboy

I've been doing a lot of research on this lately... If you want to keep the stock balance, go with the 235/295 (with 10 mm more front and back). I've found the C4S inherently understeers a bit and going with the 225/295 will only make it more so. Just in case you cared about that sort of thing... if not, and all you are planning on doing is street driving, go with either. Cheers...

J.B.H.

I wanted to go 235/295 for the same reason you mentioned...but, worried about screwing up the all wheel drive. Was also a little concerned about the extra width up front because my car is about RS height but doesn't seem like that will be a problem based on what I've read...

cafebisque

I have 235/295 on my C2S, but have noticed that the 235 really throw up quite a bit of rocks towards the outside of the well, chipping the paint pretty badly. But they do fill the well nicely. Never noticed it before with 225s.

Cheers.
______________________
08 Volvo xc70
07 Range Rover HSE
01 Lamborghini Diablo 6.0
97 C2S
91 Ferrari Testarossa
90 C2 Cab

the_buch

It varies a bit from tire to tire, and I went with 235/295 on PS2s as the math I did suggested just a tiny bit more loading/bias towards the front with the viscous coupler and still well within spec. Either setup will be fine with your 4S.

J.B.H.

So either is fine...at the end of the day would you do 235/95 again or go back to 225/95?

Stealth 993

Humm, I got to look at mine, but I thought they were 235/295?

I did just put the Sumi HTZ-III's on the 95 C4, & so far so good. Steering feel is little less crisp, wet traction is better, they are FAR quieter, & ride softer. They should wear longer. I have not played with ultimate grip yet, but so far they are 80-90% of the S02's & about 1/2 the price!

jungleboy

Depending on which brand/model tire you go with, the difference we're talking about is .1" to .2" and from all the discussion on the topic, no one seems to be worried about it with that small a percentage. The stock setup itself with 225/285 has a .1" difference. The extra width I don't think would be a problem, folks have gone wider...

NoSubEDU

I ran running 235/40/18's in front and 295/30/18's in rear. Car was lowered and had no rubbing issues whatsoever.

Now I'm running a 245/40/18 tire in the front. I've had to remove the fender well panels and use a 4mm spacer in front in order to get the rubber to clear without hitting.