Tire pressure 335 / 275

[Matt B]

While I was just adding some tire pressure to my hibernating Z, I was wondering what is a recommended tire pressure for a modern 335/275 Michelin combo?

My experience with 335 on the rear is that on 11" rims there is a tendency to more "roll" as the wide 335 tires become a bit wobbly.

So, those who ride on 335 Michelins, what pressure do you apply to them?

[WARP TEN]

When I had my Zs I put Michelin 335 rears and 275 fronts on the '95. I always just used the factory recommended settings for tire pressures. The 335s are very similar to the 315s and the 275s as I recall were the OEM size. Unfortunately I don't recall the exact factory PSI settings but they are easy to find. --Bob

[dredgeguy]

Hi Matt, I have the Michelin PS2 and used the factory setting, 35PSI cold setting with no issues.

[Z51JEFF]

I run about 42 PSI in a 325-30/19.

[Matt B]

Thanks! So I'll set both ends to 35. I already tried various settings but with no really satisfying results.

It might be that (in particular) my rear end needs a set of fresh bushings to minimize that feeling of roll during cornering.

[Mikey]

Matt,
Sloppy "roll" feeling in cornering is not usually noticed with 5 lb difference in tire pressure. That feeling is usually related to suspension related components and for sure the bushings you mentioned could be a culprit.

tire pressure variances mostly affects grip, so if you find the car not turning in, oversteer, understeer or lack of grip under accelerations then tire pressures is one of the easiest things to adjust first.

modern tires may require different settings than what the door jambs indicated in the 1990's, but it is difficult to say which is best. My C6 Z06 door jambs call for 30psi cold and I have gone to that setting on my '91 ZR-1 with happy results. Better grip on acceleration and good room for growth as the tires heat up (usually end up 6-8psi higher if at the track for example).

35psi is really borderline for cold psi. I think you are giving up considerable grip running the tires this high. Of course the tires will last longer, and maybe a slight increase in fuel mileage, but these are not usually the goals of a ZR-1 owner..

Try 30-32psi front and 28-30psi rear is my recommendation.

Cheers,
Mike