TAI2

I am interested in getting Nitto NT-01's and find that they do not offer the size I am interested in (or think I should get). I currently run 225/40/18 up front and 265/35/18 in the rear. The 275/35/18's are the closest size that they offer for the rears. I used a tire size calculator and it says that the 275/35 rears will rotate slightly slower than the 265/35's as they are slightly taller (approx 1/4"). When the car is really going 60 it will read 59. These tires are for my AutoX and DE days and am wondering how performance might change. I am thinking that if the tires are rotating slower, there might be a tendency for the car to bog down while in 2nd coming out of slow corners? I am also wondering about additional understeer as the grip will be better in the rear with the slightly wider tire. At one point I had 225's on the front and 285's on the rear and the car understeered/pushed too much in the corners. Anybody have experience here? Thanks.

CornerCarver

The setup is 235/40/18 up front and 275/35/18 in rear. Ask Dave (007) if you don't trust me.

TAI2

Hey Al, how are you doing? Heard you are selling your car - is there a Turbo in your future? Anyway, will the 235's rub? My car is lowered but about 1/2" higher than yours. Thanks buddy.

Bill Verburg

the taller rear tire raises the speed in each gear a tad(~.5mph in 2 and ~1.5mph in 6) and makes the car accelerate a tad more slowly(yes, you can feel the difference easily)

w/ a stock 993 trans 235/40 & 285/30 would do the opposite of the above and is what I would prefer if it were mine

bart1

Would 235/40 and 285/30 work okay with a C4? That is taller in front and shorter in rear than the 225/265 stock 18 combo.

TAI2

Thanks guys. I'll let you know what I do and the results. I have a couple of AutoX's coming up and a DE.

Bill Verburg

I forget if the awd spec is 2.5% or 5% max difference front to rear. whatever it is I'd make every effort to have 0% difference on the awd cars.

For abs the spec is max 5% f/r difference

jungleboy

Bart,
That's what I am running now on my Sumitomos. I did the calculations a year back and they were within the acceptable limits... I forget the details now but that combo has given me no issues on my C4S. If you go to tirerack and look under the specs portion for each tire, you'll find the diameter of the tire and better yet the revs per mile - you want to keep that front to rear ratio pretty close. I'll see if I can dig up my research. But the sumis (I see that you've got them on your car) come out to a difference of 2.26% front to back, if that helps any.