All tires will need to be replaced eventually, and trailer tires are no exception. But how soon is eventually? Are they like your typical car and truck tire, many of which have a tread life of 50,000 or 75,000 miles? And what makes a trailer tire so special, anyhow?
We wanted some straightforward answers, so we dove headlong into the world of trailer tires. Spoiler alert: if you’re new to trailering, you’ll be disappointed to know that trailer tires generally don’t last very long. To understand why, we’ll need to get up to speed on these magic rubber rollers we know as tires. But first, that straight answer we promised:
How Long Do Trailer Tires Last?
The short answer is that trailer tires should last about five or six years before requiring replacement. That’s not far off the recommended lifespan of automotive tires.
The mileage you can expect out of your trailer tires is another story altogether. While car tires can be expected to travel 50,000, 75,000, or maybe even 100,000 miles before reaching the end of their tread life, you’ll be lucky to see 30,000 miles on a trailer tire. Why?
Much of it has to do with the usage of trailer tires. For most owners, trailering is an occasional activity: the family camper or boat is trotted out a few times a year each summer before returning to long-term storage. That inevitably means the trailer is sitting around for long stretches of time. And odds are that the trailer is parked outside, where it’s at the mercy of wild temperature swings and relentless UV rays.
All that sitting isn’t good for any tire, and inevitably it will begin to dry rot – in other words, internally decompose.1 Looking at the tire won’t provide any clues to the potential degradation occurring within the tire. Only when cracks begin to appear on the sidewall will you be aware of what’s happening under the surface. At that point, you won’t want to postpone tire shopping any longer.
Another important factor is the stresses the tire is subjected to under normal use – specifically the internal heat generated within the tire during ordinary driving. Traveling down the road at highway speeds results in tremendous heat within the tire; that heat is wearing out the tire. As speed increases, so does the internal temperature of the tire. Run any tire too hot for too long and the result is a violent blowout.2
To reduce this risk, trailer tires are typically rated for a top speed of 65 mph.3 Any faster than that for long stretches of time will drastically shorten their lifespan.
You might be wondering why trailer tires have such low thresholds of heat and speed, considering that nearly all car tires can safely maintain speeds of at least 100 mph. For that, we need to consider the design differences between automotive and trailer tires.
Not All Tires Are Created Equal: Automotive Tires vs. Trailer Tires
Though all tires look fairly similar at first glance, that isn’t the case. Trailer tires are their own breed, a distinct subspecies uniquely adapted to the rigors of towing.
Tires designed especially for trailers are denoted by the ST – Special Trailer – designation that’s clearly called out on the sidewall.4 Compared to automotive tires, ST tires are taller, narrower, stiffer, and must be inflated to a much higher PSI. Their tread design is shallow and their ribs – those circumferential bands of tread that stick the tire to the road – are cut straight.
All of these elements play a role in improving the towing experience. The straight-cut ribs help improve tire cooling and gas mileage; the shallow tread reduces rolling resistance; the stronger, stiffer sidewall can support more weight than an automotive tire. When traveling at highway speeds with a fifth-wheel camper in tow, all these things matter.
However, some trailer owners aren’t sold on ST tires and may instead run what’s known as LT tires. These Light Truck tires are designed, as their name suggests, for light pickup trucks and SUVs.5 Their larger shape, complex tread, and overall design is more akin to a car tire than a trailer tire.
The reason LT tires are popular alternatives to ST tires is largely due to quality and perceived longevity. Many have complained about blowouts with ST tires; it’s been a known issue in the trailering community for years. LT tires can also comfortably maintain higher speeds.
The problem with LT tires is that they aren’t designed for trailering; they’re designed for trucks. That means they are designed to steer and accelerate and provide some degree of ride comfort. All those attributes are at odds with the qualities required for a good trailer tire, including stiffness, weight management, and minimum rolling resistance.
While an LT tire may seem like an adequate stand-in for an ST tire, we wouldn’t recommend it. A proper trailer tire will make for a better towing experience by providing superior stability and fuel economy. And if you can remember a few simple maintenance tips, your trailer tires should last a full five or six years.
How to Make Your Trailer Tires Last
We noted there is concern among trailer owners about ST tires suffering from blowouts. That’s true, and in some instances, these blowouts can rightly be blamed on subpar manufacturing methods. However, many blowouts can be prevented by properly maintaining your tires.
One of the most overlooked issues with trailer tires is keeping them properly inflated. Unlike LT tires, ST tires require much higher PSI – depending on the weight of the trailer, this could mean as high as 100 PSI.6 If you want to get into the nitty-gritty of inflation rates, see this table from Goodyear, which has everything you ever wanted to know about load and inflation ratings.
You can also improve the longevity of your tires by ensuring they’re not overloaded with too much trailer. Each individual tire has a maximum load-bearing rating; multiplying this figure by the number of tires on your trailer – presuming your trailer is properly fitted with the same type of tire all the way around – gets you the maximum trailer weight your trailer tires will be able to collectively bear.7 This figure should be 10 to 20 percent greater than the maximum weight of your camper or loaded trailer. Getting too close or even exceeding what your trailer tires can handle will very quickly lead to premature tire failure.
And one last point: when storing your trailer, see if you can lift the trailer off the ground if possible. If that isn’t feasible, at least wrap the trailer tires in protective covers (such as these) to protect them from the elements. Both actions help deter dry rotting and other maladies that arise from sitting.
Parting Thoughts
Even in the best of conditions with the most meticulous of owners, trailer tires won’t go nearly as far over their lifetime as an automotive tire. Much of this has to do with the construction of trailer tires and the limited, sporadic nature of typical trailering.
However, properly maintaining your tires and choosing the right tires go a long way in ensuring you get the most life out of your trailer tires. By being conscientious of the simple maintenance tasks we outlined here, you’ll be more likely to get more happy miles out of your trailer tires – and less likely to be repairing a blowout on the side of the highway. And if you think it’s time to replace the tires you’ve got now? Check out our guide on the best trailer tires out there.
Article Sources
Motor Sports Village uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
- Goodyear. What Causes Dry Rot in Tires and How to Prevent It. Goodyear.com. Accessed April 20, 2021.
- Dunn Tire. Extreme heat can cause tire blowouts. Dunntire.com. Published July 25, 2011. Accessed April 20, 2021.
- NATM. Dealer Corner: Tire Load Index & Speed Rating. Natm.com. Published September 26, 2019. Accessed April 20, 2021.
- Polk M. Trailer Towing – ST Tires vs. LT Tires. RvingwithMarkPolk.com. Published November 8, 2012. Accessed April 20, 2021.
- Tyre Size Calculator. Light Truck Tire Designations – Examples. Tyresizecalculator.com. Accessed April 20, 2021.
- Goodyear RV Tires. Tire Inflation & Loading. Goodyearrvtires.com. Accessed April 20, 2021.
- RVTires.com. How to Determine Tire Load Capacity. Rvtires.com. Accessed April 20, 2021.
