DOT tire safety regulations
Occasionally I will get questions about some specific feature in a tire or why tire engineers didn’t design tires to perform in a different manner. Sometimes some even want to question why I didn’t design a tire to perform some task such as supporting more load so the RV owner wasn’t forced to buy a more expensive tire.
The primary reason is that there are numerous federal safety regulations that all tires sold in the U.S. for highway use must pass or face fines that could be as high as $1,000 per tire. For those who think they can do a better job of designing tires, I can save them some time when they do the research themselves so they can ignore people such as myself who do have experience on the subject.
Safety regulations
For those interested in the various safety regulations as they pertain to vehicles, you can start HERE: 49 CFR Ch. V (10-1-06 Edition).
Then start digging down to the appropriate specific standard.
For the first 40 years of my 50+ year career, I had to live every day under Chapter V, National Highway Traffic Safety Administration, Department of Transportation, and most of the time focus on section 571 (but occasionally confirm other sections such as 569, 573, 574 and a few others).
I found myself most concerned with Sub Part B and 571.109, 571.119, and, of course, 571.139, depending on the type and size tire we might be tasked with developing or evaluating.
Good luck with your research and education.
To quote Monty Python: “And now for something completely different.”
What information is on your tire sidewall?
I bet that few of you have ever bothered to read and copy down the important information provided on your tire’s sidewall. There are a number of reasons for you to spend the few minutes it will take to collect and write down the information.
Record the DOT serial number for each tire. They might all be the same or each tire could be unique. The complete 10- to 14-character code would be used if you have a failure and want to file a complaint with NHTSA, the division of the U.S. DOT that is responsible for initiating recalls of vehicle components that have been judged to not meet the safety standards that DOT establishes.
For tires, the DOT serial number is used to identify which tires are being recalled, and replaced for free. Without the serial number, you have no way of knowing if your tires are subject to a recall or not. It is definitely a lot easier to plan and to collect the serial number on a nice sunny afternoon, than on a rainy morning in the mud. You need to include all the letters and numbers, especially the last 4 numbers, which are the “Serial Date Code” that identifies the week and year the tire was manufactured. Here is an example of an older 11-character serial number.
In this example, the date code is 3908, which would correspond to the 39th week (October) of 2008. If you have a tire this old, I would strongly recommend you replace it ASAP, as it is well over the 10 year maximum age limit for any tire in RV application.
When you start looking at your tires, you may find something that looks similar but the last four characters are not numbers. This means you need to inspect the other side of the tire, as not all tires have the date code on both sides.
Roger Marble
Check out my Blog www.RVTireSafety.Net
Read more from Roger Marble on RVtravel.com.
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Thank you, Roger! I have our RV tire sizes in my phone, but not the date codes or the DOT codes. I’ll add those once I return to our RV and record them. A recent web search indicated that our RV tires (Michelin XRV 305 70R 22.5) are slightly more than $1000/each, so I’ll take very good care of them. I’m sure regularly reading your column and covering them when not in use will be a great assist in reaching that goal.