Trailer Tires MATTER!
The Importance of Selecting the Proper Tire
Story By: Cody Carney
Photos By: Brandon Bunch
When towing our toys to the trails, the dunes, or even the lake, we all know the one issue that always seems to pop up on us at the most inconvenient times. It’s a purchase that time after time, we push to the side, telling ourselves we can go one more trip before taking a sledgehammer to the piggy bank for that last minute investment. If you guessed this scenario to be the tires on your trailer, you’d be correct.
Whether you use your trailer on a regular basis, or you’re the person that will throw it in storage to sit all but a few days out of the year, we all eventually have to replace our trailer tires. It’s not a matter of IF we need tires, it’s a matter of when. Buying trailer tires is generally not an exciting purchase, something we don’t want to have to do or spend a lot of money on. This means we have to find the correct tire best suited to how we use our trailers, ensuring that we won’t be left stranded in the middle of nowhere unexpectedly spending excessive time and money in a tire shop showroom.
The question is, “How do you find out which tire best suits your needs?” Fortunately, there is a massive market for tires. Each built with specific construction to offer quality for different circumstances. When shopping for new tires for your trailer, it’s good to note that there are tires designed specifically for trailer use. These tires often start with ST in front of the size, which stands for “Special Trailer”. There are also automotive tires such as: P-Metric, Metric, Light Truck, and Flotation tires.
Though automotive tires are sometimes seen on trailers, it’s not usually recommended to do so. Simply put, they’re just not built to withstand the extra abuse that tires on a trailer are subjected to. ST radial tires have larger steel cords and much stiffer sidewalls in their construction, that are specifically designed for high weight carrying capacities. One benefit of ST tires on a trailer, especially for double-axle or triple-axle trailer instances, is that they won’t “fold” like a passenger rated tire would when turning in a tight radius.
The P rated tires, most commonly found on cars or light duty trucks, are designed primarily with ride comfort in mind. This means they must be soft, and be able to flex with the bumps in the road while driving. This feature is great for driving a light passenger vehicle, but is not so great for carrying heavy loads for a long period of time. The constant pressure and heat caused by the flexing and swaying of the sidewalls may cause the tire to completely fail (even when brand new), wear out prematurely, or even cause a loss of trailer stability. This is important to consider because most trailer tire failures are due to overloading, under-inflation, or uneven distribution of weight. This is not something that always happens right away, as these conditions can compromise the structure of the sidewalls gradually over time.
During debates on this subject, you may hear that automotive tires typically have a longer life expectancy than ST tires; this is because tires on a trailer are subject to more weight and more stress on the sidewalls. In other words, even a P or LT rated tire with a normal life expectancy of 6 years may diminish quickly because of the conditions tires on a trailer endure. Another argument may be that automotive tires have a higher speed rating than trailer tires, no argument there as most trailer tires are rated for just 62 MPH (or less).
With a 62 mph speed limit in consideration, one option for those needing a high-speed trailer tire would be the ST rated Carlisle Radial Trail HD, which is rated to travel at speeds up to 81 MPH. We chose to equip our own enclosed trailer with this exact tire, as we frequently travel interstate highways that permit higher speed limits when towing. When conditions allow, we know we can safely travel at 75 MPH rather than having our maximum speed limited by tires with a low speed rating.
When making the Radial Trail HD, Carlisle had also put into consideration other struggles that some trailer owners might cross rubber with. To better fulfill the need of having a tire that can sustain higher loads in certain smaller sizes, the Radial Trail HD is offered in two different weight ratings. For example, say you have a 14 foot single axle flatbed trailer that runs a 205/75R15 sized tire, and weighs roughly 3200 LBS with a Can-Am Maverick X3 Max loaded up. If this trailer was equipped with an average passenger rated tire, the two tires would be very nearly overloaded with a combined weight rating of 3218 LBS, while a pair of 6 ply Radial Trail HD tires of the same size would be capable of carrying 3638 LBS, giving a little bit of breathing room between the actual weight of the trailer and the max weight rating of the tires.
However, if that Maverick happens to be loaded down with accessories, and the trailer is packed to the brim with spare fuel and other gear for a long trip, adding on a significant amount of weight, the 8 ply Radial Trail HD would be your best option with the two tires having a combined weight rating of 4298 LBS. The further you stay away from the tire’s maximum load rating, you will encounter less sidewall flex and the cooler they will run, which will extend the lifespan of your tires especially if traveling where ambient temperatures are high.
With all of that said, you do have a lot to think about when purchasing new trailer tires. First you need to know the tire size required, where you will be towing your trailer, and most importantly, how much weight you will be carrying. A trip to a reputable tire shop (such as our favorite, Discount Tire) can make this process a whole lot easier as the salesmen will be able to determine what tire will best suit your needs, and they generally have a large selection of tires at different price points in stock. Once equipped with your shiny new rubber, the main thing to remember is to always check your tires to ensure they are at the correct pressure before you head out on a trip, and be sure to check for damage or uneven wear once you return. These practices will ensure your time is spent out on the open highway, and not on the side of the road or sitting in a tire shop waiting room.
