Will my Michelin Summer Performance tires be ok ?

[KAOS]

Without being moved for two months?
As per the Tire Rack tech pages, as long as they are in a garage with temps above freezing, they "should" be ok. Pressure is 33 for all 4 tires.
---> After all, they are on my '22 HTC Z51 with a build date of 13 OCT (thanks Shane from the Museum for this info!). Thoughts?

[Foosh]

Yes, they will be OK stored above freezing. I wouldn't drive on them at temps below 40. You can "granny drive" and be OK as long as no one gets in your way, but sudden stopping and ability to make evasive maneuvers are compromised by the lack of grip.

[KAOS]

Thanks Foosh! (cool handle BTW)

[John]

As Foosh noted… Your tires will be perfect. If you want to feel 1% more reassured, what I do it to pump mine up up to 40 PSI before I start my long term storage (which can be up to 8 or 9 months for my winter tires, and during that time I rotate them 90 degrees every three months.

[KAOS]

1% indeed! Many Thanks John. I will do just that......(I just 'aint happy unless I get to worry about sumthin//sumthin).... I actually forgot to pump the tires before we left for CA/HI/CA and I think 40 is the perfect number - IMHO.
Thanks again John

[John]

Never had an ounce of flat spotting since someone taught me that. With my winter tires starting at 40, even after eight months with tires losing about one PSI/month through the sidewalls, they were just perfect when I was getting to put them on in/around Nov/Dec.

[KAOS]

So, final inquiry...how did you arrive at 40psi? I know that, in my previous life as a Porsche guru, I recall coming across more than one article/post stating that 50psi was the optimum number. Altho' I consider myself fairly educated in tires, I always felt this (50) was too high. Anyway.....

[John]

A smart friend told me to use 40 PSI before storing my years (regardless of length of time) about 30 years ago and I have used it since. It has worked perfectly. Never once put them on to experience foot spotting or other issues. They need to be high enough over standard so when they lose the 1 pound per month, they do not end up after an 8 or 9 month winter storage to still be a little above the standard, OM recommended usage PSI.

I do not however go OCD and figure out for summer tires that since they are only going to be off for 3 or 4 months to subtract that difference from 40 PSI and store them with say 36 PSI. 40 just works excellently for all.

[KAOS]

Many Thanks John!

[Ragtop 99]

Just curious, has Michelin put out any guidance? I had one tire dealer express concern that being over-inflated by 20% or more for an extended period can stretch the sidewalls and how the beads seat.

[RKCRLR]

The tires are rated for 51 psi. 30 psi is recommended for the C8 to get best ride, handling, and wear on the street. Inflating to any pressure less than or equal to 51 psi won't damage the tire.

[Foosh]

I've never overinflated for storage. Any flat spotting that may occur is not permanent and will disappear relatively quickly as soon as the car is driven again. It used to be an issue many years ago, but not since the advent of radial tires.

[meyerweb]

Somewhere recently I read an article either written by or quoting a tire manufacturer saying that over inflating tires for storage is worse than just leaving them at normal pressure. My cars don't generally sit more than a few weeks, but I've never noticed flat spotting on any tire since they stopped making bias ply tires with cotton cords.

Continental, however, says inflating to maximum pressure is OK:


http://continentaltire.custhelp.com/...~/tire-storage

[Milliwatt Rob]

FROM MICHELIN

Will over-inflating my tires help prevent flat spotting?


No, in general over-inflating your tires will not help flat spotting. In some cases it could make it worse. We recommend placard pressure and not higher.

source

https://www.michelinman.com/auto/tip...-flat-spotting

[LJT]

Michelin Owners Manual:
STORAGE Tires contain materials to protect their outer surfaces from ozone and weather checking. As the tire rolls and flexes, those materials continually migrate to the surface, replenishing this protection throughout the normal use of the tire. Consequently, when tires sit outdoors, unused for long periods of time (a month or more), their surfaces become dry and more susceptible to ozone and weather checking, and the casing becomes susceptible to flat spotting. For this reason, tires should always be stored in a cool, dry, clean, indoor environment. If storage is for one month or more, eliminate the weight from the tires by raising the vehicle or by removing the tires from the vehicle. Failure to store tires in accordance with these instructions could result in damage to your tires or premature aging of the tires and sudden tire failure. When tires are stored, be sure they are placed away from sources of heat and ozone such as hot pipes and electric generators. Be sure that surfaces on which tires are stored are clean and free from grease, gasoline or other substances which could deteriorate the rubber. Tires exposed to these materials during storage or driving could be subject to sudden failure. One reason why your spare tire should be included in the tire rotation schedule is that temperatures in a vehicle’s closed trunk, especially in sunny geographical areas, can become high enough so that, over a sustained period, they can cause small cracks or other changes to the properties of a tire stored in the trunk. An accumulation of such changes can weaken the tire and, especially if the tire is not kept properly inflated, make it unsafe to use when it is needed.

TireRack:
Z51 Tires:
Note: Tires exposed to temperatures of 20 degrees F (-7 degrees C) or lower must be permitted to gradually return to temperatures of at least 40 degrees F (5 degrees C) for at least 24 hours before they are flexed in any manner, such as by adjusting inflation pressures, mounting them on wheels or using them to support, roll or drive a vehicle.

C8 Owners Manual:
High performance summer tires have rubber compounds that lose flexibility and may develop surface cracks in the tread area at temperatures below −7  C
(20  F). Always store high performance summer tires indoors and at temperatures above −7  C (20  F) when not in use. If the tires have been subjected to −7  C (20  F) or less, let them warm up in a heated space to at least 5  C (40  F) for 24 hours or more before being installed or driving a vehicle on which they are installed. Do not apply heat or blow heated air directly on the tires. Always inspect tires before use.