I had someone point out that the Sept issue of CR had a couple of pages on RV Tires and wondered if I could offer my opinion. I do not subscribe to CR, as I have been less than impressed with some previous articles over the years. But I went to the local library and borrowed a copy.
I just finished the six-page article and will start off by saying my opinion of CR and their information on tires has not changed. "Danger on wheels" might give some the impression that this expose is based on a broad investigation into tires in RV application, when in fact almost the the entire article is on a single line of Goodyear tires that was in production 20 years ago. The G159. There is a lot of information on lawsuits and lawyers, but I found no hard data on tire durability or test data or failure analysis from CR.
While I have no personal knowledge of the G159 or any specific failures of the subject tire I was disappointed that the only warning CR provided was that tires should be removed from RV service "at 10 years old from date of the manufacturer".
As an engineer, I would prefer to set aside claims and innuendos and focus on facts and data. CR did offer what they called "9 Tips for safer RV travel". Of these only three even mention tires. One is the recommendation to replace tires that are 10 years old. Readers of RVTravel.com and of my RVTireSafety blog already know that 10 years is the MAXIMUM tire age with shorter usage time often recommended. Some are as short as 3 years in certain applications.
The article did point out that "about 40,000 G159s" were placed in RV
service and that 72 RVs suffered tire failures. Given that 22.5" wheel
size would suggest Class-A usage with a normal 6 tires per RV those
numbers suggest over 6,000 "sets" of G159 were applied and possibly as few as
1.2% of RVs suffered tire failure. No mention was made of how many of the
72 failures were the result of under-inflation, overloading, puncture, or impact. I too often see that any tire failure is blamed on the tire yet very few of those claim include any forensic inspection or identification of the mystery "defect".
A second recommendation from CR was to invest in Tire
Pressure Monitor System. I completely agree that every RV should be equipped with a properly programed TPMS. They said that "The better systems involve
fitting a sensor inside the tire." I wonder what testing CR did to arrive at that suggestion. Where is their data that supports the notion that internal to a tire somehow performs better than the more normal external, valve stem mounted sensors? I have never heard of CR doing any long term, direct comparison testing and evaluation of the different TPMS application as I have been doing for the last three years.
It is a bit of a stretch to
suggest that "balance the weight in your RV" to reduce tire wear is a
strong safety recommendation. They do suggest that the weight in the RV
should be based on the capacity of the RV but no specific mention of
confirming that no individual tire should be measured to confirm its
loading. They didn't even educate their readers on how to know the weight limit on their tires.
Is there a technical problem with the GY G159? I do not know and the CR article only uses inference and suggestions that the ire was "related" to or "associated" accidents but I saw no evidence of what the claimed "defect" might be or if there even is one in the G159. There is a small mention that some owners might have lowered the tire inflation but no mention if that act resulted in tires being overloaded.
In my opinion, CR might get a few additional sales of their magazine but the article certainly did not offer any insight into how to prevent tire failures in RV use or into the importance of never overloading or under-inflating tires.
##RVT1013
Another tire engineer here!
ReplyDeleteThings that neither CR nor Roger mentioned:
The tire in question has been out of production for 20 years!
The tire is NOT an RV tire. It's a short haul tire. How did it end up on an RV? Probably because the RV converter ordered the chassis from the chassis manufacturer without specifying the tires - and they come standard with short haul tires because that's what these chassis's are usually used for. That means the problem isn't the tire manufacturer - it's the RV converter!