RV trailer tires safety and tips

Codi JohnsonRV Tech Tips

Today we’re going to talk about trailer tires, also known as ST tires. Now the important thing that you need to know when we’re choosing tires is that there are different types of tires; for instance you have passenger tires, your LT tires along with your ST tires. ST stands for Special Trailer, while LT stands for Light Truck. Now, on our rigs we always want to go with ST tires, the reason being as they have a stronger sidewall than on LT or passenger. If we put LT tires on our trailer, we would have softer sidewalls, which would allow for some sway, so you’ll definitely want to choose ST tires. 

Now, all tires have information on them so let’s go over it so you know what you are looking for. So the first thing we want to know when we’re talking about trailer tires is the age. Age is very important, and we don’t simply look at the tread, because in our rigs we tend to travel less over time, so we don’t wear down our tread. What we need to look at is the DOT date, so you’ll spin the tire around until you see four numbers that are circled, and those four digits will tell us the date the tire was born. The first two digits will give us the week of the year and the last two digits the year it was made. 

Once you determine the date on your tire, the NHTSA recommends that all tires be changed out between 6 and 10 years, or check with the manufacturer. I would suggest that you keep it between 5 and 7 years. Remember, these are wear items and we don’t want to wear them out because when do they go out?  When we’re on the road, of course. So again, I would go ahead and change out your tires every 5-7 years, but the NHTSA suggests between 6 to 10 years. 

So the DOT date was one thing to look at, now we let’s discuss load rating. If you’ll notice on our ST tires, they give us two different forms of load rating, which are single axle and dual axle:

So, you need to know whether your rig is going to be a single axle or dual, and possibly even a triple. If it’s a double or triple, you need to go with the smaller number.

If you hit a bump, what are the chances that one tire is going to handle more weight than the rest of them? So what the engineers have done is determined what that weight factor will be; so if you go with a tandem axle or a triple axle, you’ll need to go with the lower weight rating. 

And finally I’ll go over weight ratings. ST tires are specifically designed to handle loads and that’s what we really want. We will look at the total weight of our RV and compare it to how many tires we have. The one thing we want to do when we’re upgrading tires is to increase our weight rating. Usually when we increase our weight rating, we’re going to increase our middle number. In this case we have 205/75/r14.

If I were to increase this, my middle number may change to an 80, and then the profile of my tire will stand up maybe a quarter to half inch taller. So, be aware that whenever you upgrade, your middle number may increase, so you want to make sure that you have clearance in your wheel well.

And there’s your Tech Tip!

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