Michelin warranty is 6 years BUT read term and condition from Michelin

http://www.michelin.com.my/Buying-Guides/W...odFwYA_w&247SEM

The tire should not cracked due to hardening prematurely. Normally the shelf live for tires are 6 years. If you buy tires with manufacturing date on Jan 2000, then I think the warranty period will also no be from the date of purchase I presumed. The warranty also mentioned about climate and ozone effect. They can use this to say that the hardening was due to this factor

So the best is to get to Michelin authorized shop for confirmation but make sure you bought from Michelin authorized dealer in the first place or warranty not covered

This is what I said warranty statement mostly is just to attract consumer only. When it comes to compensation, they dig all kind of reasons to not paying.

I donno about warranty card but I think there isn't any. Read this statement:

Date of purchase is documented by new vehicle registration (where the tyres were fitted on a new vehicle) or original tyre sales invoice. If there is no proof of purchase, the warranty will be based on the date of manufacture.

Talk more on the new car purchased with tires. I think there is no warranty card given for any tire brand

Anyway I think the shop might not be 100% correct when saying hardening is not covered by warranty. This is a gray area. All tires can get hardened due to UV exposure, but how severe? You can probably see micro cracked on tire surface but still safe to use. Only Michelin can say how severe the crack is to justify. The shop can say whatever he likes. Most likely the person say like that to prove (by mere statement) that the shop is not cheating its customers. You can always go to authorized shop for confirmation. I don't think there is any charge in asking