RV Tire Blowouts: Are Your Tires Safe?
RV tire blowouts can happen to anyone. There are times that manufacturing defects can cause a tire to be more prone to blowing, but often, the cause can be traced back to tire care. What are the primary causes of RV tire blowouts?
Underinflation is the best way to kill a tire fast. When a tire is under-inflated, it causes the walls and material in them to flex more than they were designed to handle. We have all taken a piece of metal like a coat hanger and bent it back and forth until the metal could not flex any longer. This activity usually generates enough heat to burn your skin too.
The exact same thing happens inside an underinflated tire. As the materials flex back and forth almost 1,000 times per minute, they heat up considerably. Tire walls are meant to be flexible, but too much flexing for too long will inevitably weaken the sidewall of the tire, causing it to fail.
The type of tires used on trailers is typically rated as an ST tire. ST stands for Special Trailer tire. ST tires are designed to have a little less flex than passenger tires to hold more weight. To put it in more technical terms,
Tim Fry, senior development engineer with Goodyear Tire & Rubber Company stated, “The major difference is reflected in the polyester cords used in ST tires. These cords are bigger than they would be for a comparable P or LT tire. Typically, the steel wire also has a larger diameter or greater tensile strength to meet the additional load requirements. Because of the heavier construction for an equal volume of air space, an ST tire is designated to carry more load than a P or LT tire.” Because they are designed to be more rigid than passenger tires, flexing from underinflation will cause a blowout much faster.
Preventing RV tire blowouts
Make sure your tires are properly inflated. The tire itself will have the max cold inflation PSI stamped on the tire. If you go through any drastic weather changes on your trip, you should monitor the tire pressure as well.
Jason S. an expert at etrailer.com says, “The max psi is the safest place to keep the tires inflated whether traveling empty or fully loaded to give you best traction with an ST tire and that is the majority of the reason why we recommend it.”
The safest way to ensure your tires are properly inflated is with a tire pressure monitoring system. These devices have sensors that fit on the stem of your tires. The sensors transmit data like tire pressure and temperature to a monitor on your phone or tow vehicle.
All tires are rated to carry a certain amount of weight. If that load is exceeded, just like the underinflated tire, it will buckle and flex under the pressure. Not only will excess weight stress the tire out, but the flexing will also cause heat buildup and material damage.
RVs will have a sticker located on them with tire inflation pressure, tire size, and a number labeled GVWR. The GWVR is the maximum weight the RV is designed to handle. That includes dry weight, water, supplies, people, and everything else that might add weight to the trailer. Keep in mind that the weight of an RV can add up fast. Just filling up a freshwater tank with a 50-gallon capacity adds over 400 lbs to the rig. The sticker with the GVWR rating is usually located around the RV door.
How to tell if your RV is overweight
You can check and see if your RV is overweight by taking it to a scale. The easiest way to do that is to use one of the CAT scales that are commonly found at truck stops. A CAT scale will give you a basic idea of your overall weight, but a method known as “wheel position weighing” at RV weigh stations will be able to tell you the exact weight you are putting on each wheel.
Overall you may be under the GVWR of your rig, but if all of the weight is resting on one tire, you risk having a blowout. This article from Do It Yourself RV will tell you all about how to weigh your RV using the wheel positioning method.
There is a line that Jeff Goldblum says in Jurassic Park. “Your scientists were so preoccupied with whether or not they could, they didn’t stop to think if they should.”
The same idea can be said for towing an RV. When we are on the road with our RVs and see a speed limit sign that says 70 mph, our instinct is to up our speed to 70 mph or more. You certainly could tow your RV as fast as you please for a little while, but eventually, it will cost you.
ST tires, unless specifically stated on the tire, are not designed to be driven faster than 65 mph. Towing an RV with ST tires faster than 65 will cause heat to build up, and shorten the life of the tire. ST tires manufactured after 2015 should have a speed rating on them in the form of a letter. The ratings you will see listed on ST tires are:
- M – 81 mph
- L – 75 mph
- J – 62 mph
There is debate on RV forums as to whether you should drive faster than 65 mph, even if your tires are rated for a higher max speed. The safest option is to set your cruise control to 60 to 65 and enjoy the drive. If you are used to being the fastest one on the road, this will feel excruciating at first.
However, after a few hundred miles, you may get used to being able to see the scenery you are driving through. You may also experience less stress since you won’t have to frequently change lanes and weave through traffic. Your gas mileage will increase as well, not only saving you from a blowout but saving you money. Always remember Goldblum’s wise words when it comes to towing speed, you can, but should you?
Inspecting new tires
Just because your RV is new doesn’t mean the tires are too. How long did your RV sit on the lot before you purchased it? How long did the tires sit in the manufacturer’s warehouse before being put on the rig? These are questions you simply won’t know the answer to when you buy your RV.
Check the sidewall of the tires on an RV you intend to purchase. If there is any weathering or cracks on them, you don’t want those tires. While you are inspecting the sidewall, take note of the date that the tire was manufactured.
Tires have an expiration date and should be changed. Most places recommend changing your tires at least every six years, regardless of wear.
According to Michelin Tires, “If the tires haven’t been replaced 10 years after their date of manufacture, as a precaution, Michelin recommends replacing them with new tires. Even if they appear to be in usable condition and have not worn down to the tread wear indicator. This applies to spare tires as well.”
Check for recalls
Finally, before accepting any tire already on an RV you are buying, be sure to head over to https://www.nhtsa.gov/recalls and double-check that there is no recall for that specific tire.
Top-rated ST Tire Brands
Like everything in life, some brands are better than others and have stood the test of time to deliver a safe driving experience. If you are the type of person who will only settle for the top-rated tire, scouring the internet will consistently show three ST tires at the top of the list.
1. Carlisle Radial Trail HD Trailer Tire
This tire is noted for added protection against the heat with built-in weathering and ozone protection. It is consistently rated number one on trailer tire sites.
2. Trailer King ST Radial Trailer Tire
Notable features of this tire include:
- Center groove for consistent tracking & stability
- Enhanced shoulder design provides better heat dissipation resulting in longer tread life and even wear
- Nylon overlay construction on all sizes for superior strength and extreme durability in higher load applications
- Nationwide limited warranty
- Rims not included
3. Maxxis M8008 ST Radial Trailer Tire
Notable features of this tire are:
- Advanced tread compound designed to decrease rolling resistance for improved fuel economy and tread life
- Double steel-belted construction for added strength and vehicle towing stability
Tires have strict regulations that must be met to be sold in the United States. Some brands have better customer ratings than others. Tire Engineer Roger Marble stated that the majority of RV tire blowouts are not necessarily the fault of where they were manufactured, but are user-related. You can see his full interview in the video below.
Make sure you are comfortable with the brand of tires you choose for your RV, but also make sure to take care that you are not exceeding the limits of your tires. In other words, take care of your tires, and they will take care of you.
Track your RV maintenance
Not only can you keep all your maintenance records and documents in one place, but you’ll also receive reminders via email when maintenance is due and potentially avoid a costly repair or serious accident.