Tires: Cracks on Tires, michelin tires, micheline tires

Question
QUESTION: Why do Michelin Tires, specially 8R X 17 easily developed sidewall CRACKS (within 3 years on Motorhomes and other trucks). Is this common only to this brand.

ANSWER: Raul,

If cracks develop quickly on the sidewalls of tires, it's usually an indication of underinflation or overloading.  So the first step is to check the inflation pressure and compare that to the actual load on the tire - which means you need to weigh the vehicle.  Every tire would be best, but at least axle by axle.

---------- FOLLOW-UP ----------

QUESTION: The tires have been checked often and have the pressure according to the rating. These tires are the original specified for the Motorhome I have. I am the 2nd owner. As soon as I bought the Motorhome (DODGE CHASSIS). I replaced all 6 tires because they were already cracking eveN when the threads are still about 75% left. My friend has exactly the same Motorhome and chassis, and have exactly the same problem with the same Micheline tires. He had it replaced like what I did and followed all the instruction of inflation. Another friend has also same Motorhome Make but different Chassis (CHEV) and happens to have a different make of tire (GOODYEAR). He never had any problem with with them.
  I bought Michelin tires for my SUBURBAN (245 R 16) and within 2 years cracking is showing on the sidewall. And they are fairly deep too.
 I am just wondering if it is the make of tire (MICHELIN) that is the problem. I have heard this problem frome some other People.   
Thanks again,
Raul


Answer
Raul,

I haven't collected any data on sidewall cracking so can't say for sure if Michelin tires are more prone to this than other makes, but that seems to be the concensus.  However, those same sources seem to feel that this doesn't hurt the performance - so it muct be more of an appearance issue.  In some respects this makes sense to me, as Michelin tends to use harder rubber compounds and these are a little more prone to cracking.