For those with Michelin PS2 ZP's
 

I know we don't need another tire thread, but I did a search and came up empty.
I have Michelin PS2 ZP's, and recently swapped out wheels at a high end shop here in AZ. They filled with nitrogen, and set all 4 tires at 37 psi. I drove it to work week before last, when it was 115 or so here, and on the way home got "high tire pressure" alarms on 3 out of 4 tires.
Looks like even nitrogen expands when the pavement is 140 and ambient is 115:D
anyway, I checked them the next day, cold, and they all read 40 psi, so I let out 3 psi to 37, and confirmed inside the car on the display, and all 4 were within .2 psi.
Drove the car again late last week, and got "high tire pressure" again on the left front. Hot as hell again that day, too.
I guess my question for guys that have this tire, is what psi are you running?
I know the plate inside the door says 30 psi, F & R, but I trust this tire shop, and the tire is rated for 51 psi max, and I was wondering if I would do any harm to the tire dropping to 32 psi or so.
thanks in advance for any help.:cheers:
Chris

Trust your car not the tire shop. :thumbs:

I wouldn't run the tire any higher than 30-32 psi cold, as you've noticed how high our tire temps can climb on hot days with lot's of direct sunlight.

37 psi cold is WAY too high here in the Phoenix area, IMHO.

I ran a set of the Michelin PS2 ZP's on my Z51 coupe and they were great. I'm about to put a set on my current Z06.

You should run tire pressures close to the recommended 30 psi. And no harm done if you always run 30 psi cold. If 32 feels better to you, that's close enough, but 37 to 40 cold is definitely too high.

Ernie

Chris,

I am not sure where your tire shop came up with 37, but that is too high. Michelin's come on the ZR1 and the new Z07 option and the recommended pressure is still 30psi. This recommendation is based on an engineering assessment of the Corvette corner weights and usage application. The 51psi max for the tire is based on the max load that tire can carry. These are entirely different.

Lower the pressures to 30psi cold on all four tires and make sure the gauge is accurate.

Best of luck!

Words to live by...

Always refer to the manual or the sticker reguardless of what the "experts" tell you. Remember: Its your warranty and money not theirs.

As an aside, besides being unsafe, running an overinflated tire will cause uneven thread wear making the tire wear out sooner.

Yep - Nitrogen is a gas at ambient temps here on earth.

As a gas, it complies with the laws of physics and gas dynamics.

EVERY gas will expand in volume when heated, or if its volume is constrained in a closed container (like a tire:yesnod:) the pressure will increase.

Like recommended by others, go with the 30 psi the manual and sticker on the door tell you to use. Nothing the matter with +/-2 psi, but 37 is too high for a cold starting pressure.

I just got home from a road trip on PS2 ZP's. I set them to 32 psi cold and they got up to about 36-37 psi on the highway when the tires heat up. I run 78% nitrogen in all my tires.

Bob

Get a new tire shop.

I run nitrogen in my Goodyear F1 Supercar Gen 2 tires. I run 30 cold. I corded my stock runflats a few months ago and they wore even all across the tire. Running 37 cold will wear the center of the tire, running less than 30 will wear the shoulders. I got 25,000 miles out of the stock tires.

A couple of weeks ago I had a two day HPDE and the nitrogen was amazing. I have tracked since 2002 and have always had to bleed the tires down to 32 prior to each session. These tires with nitrogen heated up to 37, which is optimum and before the next session they would be down to 32.

:thumbs:

I find it amazing how some of you get this kind of mileage on the stock GY tires. I needed tires at 6,000, but put it off until 8,500. I only burned out twice with those tires. Nothing crazy. I always checked my tire pressure. They wore out evenly. You should have your odometer checked :lol:
BTW, I now have Michelin ZP's and inflated at 30 psi

Thanks for all the replies, guys.
I have a very good tire pressure gauge with a release button to lower tire pressure. I guess I'll be pressing it a lot this evening!
Actually, I trust my gauge more than the digital display inside the car, but I found they correlated pretty close.
Again,thanks for the help - so much for "high end" tire shop....

Beat me too it.

Been running the ZP's (at 30psi cold) for a few months now and all I can say about em is... :thumbs:

Amazing tire you'll love em...!!

I too have found 78% nitrogen is perfect.

Eric

OK...really dumb question here. Why would a "high end shop" waaay over inflate four tires on a high end sports car when the manufacturer has the pressure listed on a plate inside the door for "all" to see?:eek:

There you go Chris, the "high end shop" should pay you as a consultant.:thumbs:

In all seriousness, follow the factory recommendations for tire pressure and you'll be all set.

:cheers:

So they can sell the original poster new tires faster! :crazy2:

Tire Rack's computer printed both the torque for the lug nuts and the tire pressure on my paperwork when I bought my Michelins from them last month -- and had them install them in South Bend.

100 lb/ft
30 PSI F&R

Just what the owner's manual says.

And they had me initial that I received the "key" for my locking lug nuts.

I am not sure I would call Tire Rack "high end" but they did exactly what they should have done and the wheels are unblemished, and the car unscratched. :rock:

And no effort to up-charge for Nitrogen. Just the good old 78% N.

I hear ya...
I was there really not of my choosing and normally use Discount Tire for my other cars, but I found a deal on some HRE wheels, and worked out a swap (+$) for my stock wheels.
I told the seller I wanted the rims spun up prior to exchanging funds, and he suggested this shop, as he had purchased the wheels there. They gave me the OK, and I figured to have them somewhat responsible for the car riding OK after swapping out my tires, I had it done there.
They did have all the right equipment, and are one of the few that has a machine shop on site. The parking lot had a lot of nice cars - Ferrari, Benz, etc.
I guess the Nitrogen flunky can't read...
Here's a pic of her with 40 psi in the tires:hide:

This is what happened w/ Firestone and Ford w/ different psi recommendations. Too low or too high can cause big problems. I trust no tech at any shop. I have seen numerous mistakes. I had new tires mounted at a tire shop. I had to tell them after watching the kid do it wrong how to torque the lug nuts and in what order. Really??/ yep then I pulled out got a half block away and the Z felt darty. I pulled over and checked my tire pressures. 51lbs!!!!!! cold! In south Florida this could be catstophic! I go back to complain...the kid tells me the sidewall said 51lbs!!!!!!!!!! Idiots!

Yeah, I run 78% nitrogen too, and it is cheap and easily found.

I actually have 78% nitrogen pumped throughout my home. The family really loves it!