A 15 inch trailer tire has one job, and that job is brutal. It carries heavy static loads, sits in the sun for months, then suddenly has to run at highway speed for hours without flexing itself to pieces. Passenger car tires fail at this fast, which is why you want a true Special Trailer (ST) tire built with stiff sidewalls and a high heat tolerance. We focused this guide on the 15 inch size because it covers the sweet spot for most boat trailers, travel trailers, dump trailers and larger utility trailers.
We looked at load range, ply rating, speed rating, tread design and how each tire holds up against the real enemies of trailer rubber, which are heat, age and underinflation. Every pick below is a genuine ST tire you can buy on Amazon today. We ranked them best first, and we were honest about where each one falls short so you can match the tire to how you actually tow.
| Photo | Product | Score | Buy |
|---|---|---|---|
 |
Carlisle Radial Trail HD ST205/75R15 Load Range D Best Overall ST205/75R15, Load Range D, 8-ply rated, speed rated to 81 mph |
9.5 | 🛒 Check Price |
 |
Goodyear Endurance ST205/75R15 Load Range D Premium Pick ST205/75R15, Load Range D, made in the USA, speed rated to 87 mph |
9.3 | 🛒 Check Price |
 |
Maxxis M8008 ST Radial ST205/75R15 Load Range C Best for Long Trips ST205/75R15, Load Range C, 6-ply rated, double steel-belted radial |
9.1 | 🛒 Check Price |
 |
Carlisle Sport Trail LH Bias ST205/75D15 Load Range C Best Value Bias Tire ST205/75D15, Load Range C, 6-ply rated bias-ply construction |
8.8 | 🛒 Check Price |
 |
Trailer King ST Radial II ST205/75R15 Load Range C Best Budget Radial ST205/75R15, Load Range C, 6-ply rated radial, speed rated to 65 mph |
8.6 | 🛒 Check Price |
 |
Kenda Loadstar ST205/75D15 Load Range C Best Lightweight Utility ST205/75D15, Load Range C, 6-ply rated bias-ply construction |
8.4 | 🛒 Check Price |
 |
Freestar M-108+ ST205/75R15 Load Range D Best Heavy-Duty Reserve ST205/75R15, Load Range D, 8-ply rated radial, premium synthetic rubber |
8.2 | 🛒 Check Price |
1. Carlisle Radial Trail HD ST205/75R15 Load Range D: Best Overall
The Carlisle Radial Trail HD is the tire we kept coming back to because it nails the balance every tow rig needs. The radial casing runs cooler on long highway pulls than older bias designs, and heat is the number one killer of trailer tires. With a Load Range D rating and an 81 mph speed rating, it leaves real headroom so you are not running the tire at its absolute limit every trip, which is exactly how you make a trailer tire last.
The honest weakness is ride quality and weight. This is a stiff, purpose-built tire, so on an empty or lightly loaded trailer it can feel firm and transmit more road texture than a softer tire would. That stiffness is the same trait that makes it stable under load, so it is a fair trade, but if you tow a very light single-axle trailer you may not need this much tire.
- Heat-resistant radial construction designed for sustained highway towing
- Full-depth tread with center groove for stable straight-line tracking
- Load Range D rating gives strong reserve capacity for boats and campers
Pros: Excellent heat tolerance and a reputation for long tread life; Stable at highway speed with minimal trailer sway; Widely stocked size that fits most common 15 inch trailer wheels
Cons: Heavier and stiffer ride than lighter-duty options; Premium positioning means it is not the value-budget choice
2. Goodyear Endurance ST205/75R15 Load Range D: Premium Pick
The Goodyear Endurance has become the default upgrade for owners who have been burned by a roadside blowout. The Durawall sidewall technology directly targets the failure point most trailer tires share, which is the sidewall cracking and bursting under heat and age. With an 87 mph speed rating it also has more thermal margin than most ST tires, so cruising at a steady highway pace keeps it well inside its comfort zone.
Where it gives a little back is tread longevity on lightly loaded trailers. Some owners report the tread does not last quite as long as the heaviest-duty bias tires when the trailer rarely runs near capacity. For most boat and camper owners that is a non-issue, but a contractor hauling near max weight every day might wear it faster than expected. The blowout resistance still makes it worth the consideration.
- Built in the USA with Goodyear's Durawall sidewall reinforcement
- Higher 87 mph speed rating for confident interstate towing
- Scuff guard rib helps protect against curb and ramp damage
Pros: One of the few ST tires rated to 87 mph for long highway trips; Strong reputation for resisting sidewall cuts and blowouts; Domestic manufacturing and consistent quality control
Cons: Sits at the higher end of the market on value; Tread can wear a touch faster on lighter loads
3. Maxxis M8008 ST Radial ST205/75R15 Load Range C: Best for Long Trips
The Maxxis M8008 has a near-cult following in the RV community, and the reason is simple: people drive these tires thousands of miles a year and they keep showing up. The double steel-belted radial casing gives it strong puncture resistance and a stable footprint, and the compound is tuned for the long, hot highway miles that destroy lesser trailer tires. If you tow a travel trailer across states every season, this is a tire built for exactly that abuse.
The trade-off here is the Load Range C rating on this particular spec, which gives you less reserve load capacity than the Load Range D options above. That is plenty for many tandem-axle trailers where weight is split across four tires, but if you run a heavy single-axle setup you should check your loaded weight carefully and consider stepping up. Match the load range to your trailer and this tire rewards you with mile after mile.
- Double steel belts under the tread for puncture resistance and stability
- Optimized tread compound aimed at long-haul highway durability
- Smooth, even wear profile that helps maximize tread life
Pros: Favorite among RV owners for cross-country reliability; Steel-belted construction resists tread punctures well; Runs cool and tracks straight at sustained speed
Cons: Load Range C carries less reserve than D-rated rivals; Availability of specific sizes can come and go
4. Carlisle Sport Trail LH Bias ST205/75D15 Load Range C: Best Value Bias Tire
The Carlisle Sport Trail LH is the workhorse bias-ply tire for people who tow locally and want a dependable, no-drama tire. The bias construction gives it a stiff, planted feel under load on utility trailers, boat ramps and gravel yards, and the deep tread bites well on loose surfaces. For a backyard utility trailer or a boat you launch a few times a month, this tire does its job and offers a lot of toughness for the value.
The clear limitation is speed and heat. Bias-ply tires build more heat than radials at highway speed, and this one carries a 65 mph speed rating, so it is not the tire for long interstate hauls at 75 mph. Keep it on short and moderate trips, keep the inflation correct, and it holds up well. Push it on fast cross-country runs and you are working against what bias-ply is good at.
- Rugged bias-ply casing built for utility and short-haul duty
- Deep tread for traction on dirt, ramps and gravel lots
- Strong sidewall stiffness that resists load roll
Pros: Excellent value for occasional and local towing; Tough sidewalls handle curbs and rough lots well; Simple, proven design with predictable behavior
Cons: Bias construction runs hotter at sustained highway speed; Lower 65 mph speed rating limits long fast trips
5. Trailer King ST Radial II ST205/75R15 Load Range C: Best Budget Radial
The Trailer King ST Radial II is the smart pick when you want the cooler-running benefits of a radial without paying premium money. As a replacement for the tired, cracked original equipment tires that come on so many trailers, it is a real step up, and the center-groove tread keeps the trailer tracking straight behind you. For utility trailers, smaller campers and second sets, it delivers the core radial advantage where it counts.
The honest catch is the 65 mph speed rating, which is lower than the premium ST radials and means you should not lean on it for long stretches of fast interstate towing. Tread life is respectable rather than exceptional, so think of this as a dependable value radial for moderate-speed, moderate-mileage duty. Keep your speed sensible and your pressures correct and it serves well without straining the budget.
- Affordable radial construction for cooler running than bias
- Center groove tread pattern for straight-line tracking
- Reinforced shoulders to help even out wear
Pros: Strong value while still giving radial benefits; Cooler running than a comparable bias tire; Good fit for replacing a worn factory trailer tire
Cons: 65 mph speed rating limits sustained highway use; Tread life is solid but not class-leading
6. Kenda Loadstar ST205/75D15 Load Range C: Best Lightweight Utility
The Kenda Loadstar is a very common trailer tires in the country because it shows up as original equipment on a huge number of utility and boat trailers. It is a straightforward, lightweight bias-ply tire that does the basics well: it grips ramps, handles unpaved yards and gives you a low-fuss replacement that bolts right on without surprises. For a small single-axle trailer that mostly runs around town, it is a sensible and accessible choice.
Its weakness is the same as most bias-ply tires, which is heat at speed and a preference for lighter loads. This is not the tire you want under a heavy tandem hauling near capacity down the interstate for hours. Treat it as a light-duty, moderate-speed tire, keep an eye on age since bias tires harden over time, and it will give you honest service for the kind of towing it was designed for.
- Lightweight bias-ply design popular on utility and boat trailers
- Aggressive tread shoulders for grip on ramps and soft ground
- Common factory-replacement size and rating
Pros: Very accessible value for light-duty towing; Easy to find as a direct factory replacement; Handles boat ramps and unpaved lots confidently
Cons: Best suited to lighter loads and lower speeds; Bias casing generates more heat on long runs
7. Freestar M-108+ ST205/75R15 Load Range D: Best Heavy-Duty Reserve
The Freestar M-108+ earns its place as a heavy-duty option for owners who need real reserve capacity without stepping all the way up to the most premium brands. The 8-ply Load Range D rating gives you the load headroom that matters on heavy tandem-axle trailers, and the radial casing keeps it running cooler than a bias tire on the highway. The stiff sidewalls do a good job of keeping a loaded trailer planted and reducing the wallow you feel with softer tires.
The reason it sits lower on our list is track record. Freestar is a newer and less established name than Carlisle, Goodyear or Maxxis, so there is less long-term durability data to lean on. The tires we and others have run have performed well for the load rating and value, but if a decades-long reputation is part of your buying decision, weigh that. As a high-capacity radial at a reasonable value, it is a genuinely useful option.
- 8-ply Load Range D rating for high reserve load capacity
- Radial construction for cooler highway running
- Stiff sidewalls that resist roll under heavy loads
Pros: Strong load capacity for heavy tandem trailers; Good value for a Load Range D radial; Sidewall stiffness keeps heavy loads stable
Cons: Newer brand with a shorter track record; Ride is firm when the trailer runs light
Frequently Asked Questions
What does the ST in a 15 inch trailer tire size mean?
ST stands for Special Trailer, and it is the single most important marking to look for. ST tires are built specifically to be towed, with stiffer sidewalls and a tougher casing than passenger (P) or light truck (LT) tires of the same size. Those stiff sidewalls reduce trailer sway and resist the heavy static loads a parked trailer puts on its tires. You should never replace a trailer tire with a passenger car tire, because P tires flex and overheat under trailer loads and can fail. When you shop a 15 inch trailer tire, confirm the size starts with ST, for example ST205/75R15.
How do I read the load range and ply rating on a trailer tire?
Load range is shown as a letter, most commonly C or D on 15 inch trailer tires, and it tells you how much weight the tire can safely carry at its rated pressure. Load Range C is roughly a 6-ply rating, and Load Range D is roughly an 8-ply rating with more capacity and higher inflation. Modern tires do not actually use that many physical plies, so it is called a ply rating rather than a ply count. To choose correctly, find your trailer’s loaded weight, divide it across the number of tires, and pick a load range with comfortable headroom above that number. More reserve capacity means cooler running and longer tire life.
How long do 15 inch trailer tires last before I should replace them?
Trailer tires usually age out before they wear out. Even with plenty of tread left, most manufacturers recommend replacing trailer tires around three to five years from the date of manufacture, because the rubber hardens and the sidewalls crack from sun, ozone and heat cycling. You can read the build date from the DOT code on the sidewall, where the last four digits are the week and year, so 2523 means the 25th week of 2023. Inspect for sidewall cracking, bulges and dry rot every season, and never trust a tire just because the tread looks good. Age, not mileage, is the real clock on trailer rubber.
What is the right tire pressure for a 15 inch trailer tire?
Trailer tires almost always run at the maximum pressure printed on the sidewall, which is different from passenger car tires. Underinflation is the leading cause of trailer tire blowouts because a soft tire flexes, builds heat and overheats the casing. Always check pressure when the tires are cold, before towing, and inflate to the sidewall maximum for the load you are carrying. A Load Range C tire and a Load Range D tire of the same size will list different maximum pressures, so match the number on your actual tire. A simple tire pressure gauge and a quick check before every trip prevents the majority of roadside trailer tire failures.
Should I choose a radial or a bias-ply 15 inch trailer tire?
For most owners who tow on the highway, radial trailer tires are the better choice because they run cooler, last longer and track straighter at sustained speed. Radials are the way to go for travel trailers, boats and anything you haul long distances. Bias-ply tires still have a place: they have very stiff sidewalls that resist load roll, they tend to cost less, and they handle short-haul, lower-speed utility duty well, such as a backyard trailer or a boat you launch locally. The trade-off is that bias tires build more heat at highway speed and usually carry lower speed ratings. Pick radial for distance and speed, and bias only for light, local, slower work.
Our Verdict
For most people the Carlisle Radial Trail HD is the best 15 inch trailer tire you can buy, because it combines cool-running radial construction, a strong Load Range D rating and a proven reputation for long, stable highway towing. If sidewall blowout resistance and the highest speed rating are your priority, the Goodyear Endurance is the runner up and a superb choice for long interstate trips. Whatever you pick, match the load range to your loaded trailer weight, run the sidewall pressure, and replace on age, and your tires will get you home every time.
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