Like some tires, the question “How old are my tires?” is as old as the hills—but the answer is really simple. All tires in RV application should be removed if they are 10 years old based on their DOT date code. However, there are exceptions.
This tire shows 7th week of 2020, so it is over 4 years old. All tires sold for highway use in the U.S. are required BY LAW to have a DOT serial that includes the date code as the last 4 digits. The date code only is required on one side of your tires so if you failed to record the DOT serial when you purchased your RV you may need to crawl under the RV to read the serial. You need to know the code for each tire. If you are not up to the task of getting under the RV, I suggest a $5 bill and flashlight and a 10-year-old to get the job done.
So, 10 years is the maximum age for a tire no matter what the visual inspection indicates. But what would be the “normal” recommendation for replacement?
Exceptions to the tire replacement recommendation
Last week I listened to a couple of tire field engineers from a major tire company point out that unless the tire has suffered some damage or been driven with the air pressure more than 20% low, people should expect to get at least 5 years’ use from the tires on their car, truck or motorhome. I agree EXCEPT for towables and 5th wheel trailers where, because of Interply Shear, the tire life is half of that on a motor vehicle. You can learn more about Interply Shear in this post.
So what about the 5 years between 5 and 10 years? That’s where inspection and maintenance come in.
Do you shield your tires from direct sunlight when parking for more than a day? Do you clean your tires with the same soap and cloth you would use on the side of your RV?
Tire safety tips
We are going to assume you have confirmed the actual weight on the tires of your RV and have consulted the Load & Inflation tables to learn the MINIMUM cold inflation pressure required for your application. This also means that you have installed and properly programmed a Tire Pressure Monitor System, i.e., TPMS. We will also assume that at 5 years (2.5 years for towables) you had the tires inspected by an ASE-certified auto mechanic with special training in front-end tire conditions or trained by a major tire company to inspect and issue a document that the tires are good for another year’s service.
In summary, there is a 10-year maximum age for tires no matter what. At 5 years, the tires need to be inspected (both sidewalls and 360° of the tread by a person certified by the company that made the tires) with an inspection document stating the tires appear to be acceptable for another year’s service. If the tires are on a towable or 5th wheel trailer, then the time is 5 years max, with annual inspections starting at 2 years.
Roger Marble
Check out my Blog www.RVTireSafety.Net
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Would you provide us with the actual real world data that indicates towable tires only have 1/2 the years of life as compared to a motorhome/car tire. My actual experience (I’m not a tire expert) is far different then that, I have had tires on my TT last many more years past what you are saying. I follow the 5 to 8 year schedule and have never had a tire problem of any kind. I am religious about tire maintenance.
The “5 year” is the time that Michelin Engineers feel that all RV tires should last even without special actions such as tire cover, and that the inspection should take place at 5 years. Michelin does not make ST tires for RV trailers so they have no comment. The 50% suggestion comes from the computer simulations I ran on LT type tires which have essentially the same features and construction as ST type. The issue is the 10 year MAX life may need special care and inspections you want to get to that level but all truck tires should last at least 5.
Good stuff as always Roger, but I think that 10 year old probably deserves more than $5. Inflation and all!
Roger, is the interply sheer on trailers worse than on dually and tag motorhome tires in really tight turns?
I have a 60 degree front wheel cut, so my 43′ motorhome can make some pretty tight turns despite its 288″ wheelbase (front center to drive center) plus tag. The tags, especially, get a fair amount of scrub when backing in to a tight spot, though I can let the air out of those airbags to take pressure off them. Of course, that weight is then transferred to the drives.
While I have no actual data on TAG axle Interply Shear I think It might also be of concern EXCEPT for the fact the TAG axles are not as heavily loaded as the other axles on a Class-A. It is my understanding that when doing a tight turn as you would on city streets or in a campground the tag air bags can be released to decrease the scrub on the tag axles. SO TAG axle tires would not have as much of a problem as the tires on a trailer.
What is with using the same soap that you use on the side of your RV. Is their an issue with various soaps and what is it? I use a car wash Polymer wash and wax soap. Is that bad for the tires?
Thank you, Roger! 🙂 I knew almost none of this. Thank you for informing me! Safe travels and happy Easter! 🙂