By Bill Hariu – February 2026

Everyone loves spending time out on the boat at the lake. But nobody loves being stuck on the side of the road with a blown-out trailer tire on the way to the lake. Just as you maintain your vehicle and boat, checking and maintaining your boat trailer tires is essential.

Ensuring your trailer has the right tires before you hit the water with your boat is essential. This guide explains how to make an informed tire choice Your boat deserves the best, starting with the right trailer tires.

When to Buy Boat Trailer Tires

Unless you’re buying a brand new boat and trailer off the dealer lot, you will likely be in the market for some new boat trailer tires. If you don’t know how old the boat trailer tires are, you can check the DOT code on the side of the tire. 

What Is the Tire Date Code?

The tire date code is a four-digit number found on the sidewall of a tire, immediately following the letters “DOT”. It reveals the week and year your tire was manufactured.

• The first two digits indicate the week of the year (01 to 52).
• The last two digits show the year (e.g., “2519” means the 25th week of 2019).

Knowing how to read this code is essential for tire safety, since age can affect performance, even if the tread still looks fine.

Now that you know how old your boat trailer tires are, you must evaluate their condition.

An easy way to check if you need new tires is by the tread depth. To do this, you can use the Lincoln penny trick. All you do is set the penny, with the head facing down, into one of the grooves in the tire tread. It’s best to pick a couple of spots on the tire. If you can see the top of Abe’s head with the coin in position, it’s time to start looking for new tires.

The other thing to check for is cracks in the tire rubber. Boat trailers usually sit unused for long periods. The tread isn’t wearing out when the trailer is parked, but the rubber degrades due to exposure to UV rays and freezing temperatures.

The rubber dries out, and cracks start to appear. These usually occur in the tire’s bead area close to the rim, but you may also see small cracks between the tread blocks or in the tire grooves. Even some discoloration is usually no cause for concern. Deeper cracks warrant closer inspection by a tire expert.

Valve Stem

Often overlooked, the valve stem may be the cause of continued low psi. Press your finger against one side of the stem and listen for any loss of air.

Can you use regular car tires on a boat trailer?

Using regular passenger car tires on a boat trailer is not advisable. Car tires are not designed to handle the specific requirements of boat trailer towing, which include increased load capacity and resistance to water exposure. Boat trailer tires, marked as “ST” (Special Trailer), are engineered to withstand the challenges of marine environments and ensure safe towing, making them the best choice for your boat trailer.

Five Key Steps for Choosing the Right Boat Trailer Tires

1.   Know Your Boat Trailer’s Weight: Start by determining the weight of your boat and trailer when fully loaded. This information is crucial in selecting tires with the appropriate load-carrying capacity.

2.   Check the Tire Size: Refer to your trailer’s owner’s manual or inspect the existing tires for their size. Ensure you choose tires that match the rim size and meet the manufacturer’s specifications.

3.   Choose Special Trailer (ST) Tires: opt for ST tires explicitly designed for trailers. These tires are constructed to handle heavy loads, resist heat buildup, and provide improved water resistance, making them ideal for marine environments.

4.   Consider the Tread Pattern: Select a tread pattern that suits your towing needs. If you frequently launch your boat on slippery ramps, use tires with a tread design that offers excellent traction on wet surfaces.

5.   Regular Maintenance: Once you’ve chosen the right tires, don’t forget to maintain them properly. Check tire pressure regularly, inspect for signs of wear or damage, and keep them properly inflated to ensure safe towing.

By following these steps, you can make an informed choice when selecting boat trailer tires, ensuring that your trailer is equipped for safe and smooth boating adventures on the water.

What To Buy If You Need New Boat Trailer Tires

Dedicated trailer tires are marked as ST. This will be kept on the tire’s sidewall, along with the size of the tire. The tire may also say, “Trailer use only.” ST tires have stronger sidewalls that allow them to carry a heavier load than standard Passenger car tires or Light Truck tires. There are two kinds of ST tires: bias-ply and radial. Which type of tire you buy will depend on what comes on the trailer, how you use your trailer, and your budget.

In short, bias-ply trailer tires are cheaper and recommended for infrequent short-haul applications, including off-road or heavy loading. If you plan long highway driving trips, consider replacing those bias-ply tires with radial tires. Radial trailer tires are made to run cooler for longer hauls and a longer tread life. Never replace radial tires with bias-ply tires without consulting the trailer manufacturer or a tire professional.

Load Range

Now that you know what kind of tire to buy, you must consider the tire’s size and load capacity. The load range on trailers is classified as B, C, D, or E. B is the lightest classification of load capacity, and  E carries the heaviest load capacity.

Key Takeaways  

• Check the Sidewall: Always read the specific load rating stamped on your tire, as capacities vary slightly by brand

• Pressure is Everything: Reduced PSI lowers load capacity. A 20% drop in PSI can reduce load capacity by 12%.
• Tandem Axles: If you have tandem axles, calculate for a 12% to 20% load reduction, as tires may not share weight perfectly.
• Safety Margin: Ensure your total tire capacity (combined) exceeds the total GVWR (Boat + Motor + Fuel + Trailer + everything you place in your boat) by at least 10-15%. 

Common boat tires are Load Range C (6-ply, ~1,500–1,800 lbs) or D (8-ply, ~2,000+ lbs). Crucially, match the tire’s max PSI (e.g., 50-90 PSI) to its rated 

Proper Use and Care for Your Boat Trailer Tires

Once you have the perfect set of boat trailer tires, keeping a few things in mind is essential. Even though many of us want to reach our destination as fast as possible, boat trailer tires are made not to exceed speeds of 65 mph (100 km/h). Doing so for long periods could lead to tire failure.

 If you are going to be traveling on high-speed highways, you certainly don’t want the weight maxed out.   Avoid loading up the boat with extra weight during transport. Moving heavy cargo from the boat  to the back of the tow vehicle allows your trailer tires to withstand slightly higher speeds for extended periods.

It is also necessary to take proper care of your boat trailer tires during periods of nonuse by protecting them from UV light. There are unique wheel covers. However, a standard tarp or coverage in the garage is equally effective.

The final thing to remember is to rotate and balance your boat trailer tires as you do on your car or truck. Even turning your tires side to side on a single-axle trailer will help even out irregular treadwear and extend the tire’s life.

On a double axle, the standard X rotation is in order occasionally, particularly if you notice that irregular wear patterns are developing in the tread. 

Outside Temperatures:

• Every 10-degree decrease in air temperature leads to 1 psi of air loss. If you’re traveling somewhere that the morning temperature varies greatly from the afternoon temperature, check your air pressure first thing in the morning and again as the temperature increases.

Tires aren't exciting, until something goes wrong. Then, tires become the topic of the day.  In conclusion, take proper precautions and take care of your boat trailer tires.

bill.hariu@lakeannavirginia.org