Tire pressure 335 / 275 - ZR-1 Net Registry Forums

Matt B · 12-19-2022

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 · 12-19-2022

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 · 12-19-2022

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

Z51JEFF · 12-20-2022

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

Matt B · 12-28-2022

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 · 12-29-2022

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

12-19-2022	#1
Matt B Join Date: Jan 2021 Location: Beautiful Bavaria Posts: 523	Tire pressure 335 / 275 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? __________________ ZR-1 #638/1991

12-19-2022	#2
WARP TEN Join Date: Apr 2007 Location: Lake Bluff, IL Posts: 2,048	Re: Tire pressure 335 / 275 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 __________________ 2016 Long Beach Red Z06 #10281 "POPS Z" 1995 Polo Green #409 "WARP TEN"--Haibeck 350/510 package, 4.10s, Hurst, Stock Exhaust with QTP Cutouts --Sold but still running strong 1993 Quasar Blue #161 "HIL KING" --Sold but still running strong, now with more than 120,000 miles 1967 Marlboro Maroon/Saddle Corvette Coupe 300 hp/4-spd --Sold a long time ago ZR-1 Net Registry Founding Member #95 NCM Lifetime Member Favorite Quote--Attributed to Mickey Thompson: "Too Much Horsepower is Almost Enough"

12-19-2022	#3
dredgeguy Join Date: Aug 2012 Location: Ellicott City, MD Posts: 1,638	Re: Tire pressure 335 / 275 Hi Matt, I have the Michelin PS2 and used the factory setting, 35PSI cold setting with no issues. __________________ Charlie __________ Dredgeguy WAZOO Member 1992 Bright Red/Black ZR1 #246 Dana 4:10 gears Polished LT5 by Haibeck Polished Fikse FM5's with Michelin Pilot Sport 2 Stainless Works headers and cats with Corsa

12-20-2022	#4
Z51JEFF Join Date: Dec 2007 Location: Fremont,Ca Posts: 3,052	Re: Tire pressure 335 / 275 I run about 42 PSI in a 325-30/19.

12-28-2022	#5
Matt B Join Date: Jan 2021 Location: Beautiful Bavaria Posts: 523	Re: Tire pressure 335 / 275 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. __________________ ZR-1 #638/1991

12-29-2022	#6
Mikey Join Date: Jul 2020 Location: Nashville TN Posts: 305	Re: Tire pressure 335 / 275 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