Everything You Need to Know About RV Tires

Tires are one of the most important parts of any RV trip. Here we outline the tire basics every RVer should know so you can make the best RV tire purchasing decision for your rig and budget.

How to Read an RV Tire’s Sidewall

A tire’s sidewall includes the tire’s size, max load per tire, tire construction (plies per tread and sidewall), manufacturing date, special warnings, country of manufacture, load range/ply rating, DOT code, brand name, and tread design name.

There are two numbers on the side of your tire you need to pay close attention to. You’ll see them listed as max load single (or dual) and inflation pressure (single or dual).

• The first is the max load per tire (single or dual usage). These numbers on the sidewall are smaller than the others, but you can find them fairly easily because you will see the load range written in both kilograms and pounds.
• The next most important number is inflation pressure (single or dual). This is the pressure the tire should be inflated to as recommended by the vehicle manufacturer, which may vary from the maximum tire pressure for the maximum load carrying capacity of the tire. It does not need to be inflated to the maximum load inflation pressure unless the vehicle’s weight is at or near the vehicle’s gross vehicle weight rating (GVWR). You will see this written in both kilopascals (kPa) and pounds per square inch (psi). You’ll want to use the psi number in the U.S.

Here’s an overview of what the other numbers on your RV tire mean: 

Weight Distribution and Loading Your Camper

It’s extremely important to balance your cargo throughout your rig so that the weight is evenly distributed across your axles and each tire. If one side or tire is loaded to more than its weight rating, you are more likely to experience a blowout. When loading your camper, keep in mind that certain items, like batteries or a generator, weigh more than others. You’ll also want to pay attention to your layout—if your kitchen is on one side of your rig, load cargo on the opposite side to even out the distribution. Make sure you distribute the weight equally from front to back and side to side. 

RV Tire Pressure

Tire pressure is important because when a tire fails, it will damage not only the surrounding fender skirts, but also the sidewall, wheel wells, and possibly the trim. That equates to a lot of money for repairs. You should never reduce your tire pressure below the required tire pressure for the load placed on the tire to get a softer ride on the road. Always make sure you have an accurate tire pressure gauge, and if your vehicle has dual rear wheels, make sure your gauge has an offset double head that can reach both the outer and inner valves.

Tires are designed to only carry a certain amount of weight based on their inflation. Each tire will have weight ratings printed on the sidewalls for the specific inflation pressure the tire should have to carry the maximum tire load rating. The suggested pressure will vary based on the tire configuration of your vehicle and the load placed on the tire. 

Overinflated tires will wear out sooner. As you travel down the road, heat builds up in your tires, and tire pressure increases. Keep a digital tire gauge in your glove box and check the tires once every traveling day before you hit the road.

Temperature and Altitude in RV Tires

When solids, liquids, and gasses get warmer, they expand. So as the air temperature rises, the tire pressure does too. You can estimate about 1 psi for every temperature change of 10 degrees Fahrenheit.

Altitude also affects tire pressure. The higher the altitude, the lower the atmospheric pressure, which is the ambient pressure you experience. (Gauge pressure is the pressure inside your tire.) So if you fill your tires to the recommended psi at or near sea level and then increase your altitude, you’ll likely gain 2 to 3 psi at the peak. However, as you reach higher elevations the ambient temperature drops, likely offsetting the psi increase.

Make sure you check your tires when you encounter environmental changes related to temperature and altitude. You can do so with a digital infrared thermometer. 

What’s the Correct Pressure for RV Tires?

To determine the correct tire inflation pressure for your vehicle’s tire loading, check the manufacturer’s load inflation. You’ll find this information at tire dealers and on the manufacturer’s website.

Oxygen vs. Nitrogen in RV Tires

Perhaps you’ve seen green caps on tire valves at the campground. These signify that the rig is driving on nitrogen-filled tires. Some prefer to use nitrogen because it delivers a better fuel economy and a smoother ride.

The regular air in your tires is 21 percent oxygen and 78 percent nitrogen, with the remaining contents a mix of noble gases, carbon dioxide, and water vapor. Water vapor leads to moisture inside your tires, which can lead to corrosion of your rims. It can also cause your psi to change when the temperature changes, leading to over-inflation. That’s because the moisture retains heat and will expand when it gets hotter. Also, oxygen molecules will permeate the inner lining of your tire, leading to pressure loss and degradation.

Nitrogen, on the other hand, is a larger atom than oxygen and doesn‘t permeate the inner lining, leading to comparatively longer tire life. And when your tires are filled with nitrogen, they go through a purging and filling method that eliminates nearly all the moisture. This translates into steadier pressure over the long haul. Whether nitrogen is right for you is a personal decision.

RV Tire Storage

RV tire covers are an easy way to protect your RV tires from the heat, cold, and sun and can be found online for $20 to $30. They’re easy to put on and take off and are much cheaper than having to buy new tires to replace those ruined by negligence and the elements.

If you do take your tires off of your RV at any point, store them in a dry and cool indoor environment with no air currents or direct sunlight.

RV Tire Replacement 

It’s recommended that you inspect your tires every 90 days to see if they need to be replaced.

The amount of weight you’re putting on your tires can cause them to wear out faster than they should. Failing to maintain proper weight distribution can also pop the tires that are holding the most weight.

To determine whether you need new tires, try the coin test. Use a quarter or penny and fit it into the grooves of your tires. The coin should stand straight up. If it doesn’t, then the treads are too worn-down to continue driving.

Another factor is age. If your tires are older than 5 years, they likely need to be changed regardless of how many miles you’ve put on them. All tires contain a Tire Identification Number (TIN) that identifies the week and year that the tire was manufactured. TINs start with the letters “DOT” followed by several numbers and letters. To determine the age of your tires, look at the last four digits of the TIN. Consider these digits your tire’s “born-on date.” For example, if the last four digits of your TIN are 4210, that means that your tires were manufactured in the 42nd week of the year 2010.

Tips for Avoiding a Tire Blowout

There are a few things you can do to avoid a tire blowout: Purchase quality tires that are right for your rig and stay up to date on your tire maintenance by regularly checking for wear and tear, inflating them at the correct number, evenly distributing the weight in your rig, and replacing your tires when needed based on age or wear. 

RV Tire Types

There are two types of RV tires: LT and ST. If you’re towing an RV, you’ll want ST tires. Tires with an ST designation are designed for “Special Trailer” usage. Trailer tires aren’t used for steering during acceleration, so traction is not a consideration. Their tread patterns are specifically designed for low rolling resistance. However, trailer tires do have to carry a lot of weight and endure outside storage and weathering for extended periods.

The compounds in ST tires typically use more chemicals to resist UV rays and aging, so they may use harder rubber than drive-wheel and steering tires. ST tires are typically rated at 65 mph under normal inflation and load conditions. If you plan on traveling more in the 65-to-75-mph range, you’re going to need to increase the inflation of your tires. Do not ever increase the recommended pressure in your tires by more than 10 psi. And if the maximum pressure for the wheel prohibits the increase of air pressure, then the maximum speed for your trip is simply going to have to be 65 mph. Vehicle speed should not exceed the tire’s speed rating, and pressure should never exceed the maximum inflation pressure.

Class A, B, and C RVs are more likely to use LT-metric (light truck metric) tires. In many cases, a straight-rib highway tire will work best on the front of your RV. This type of tread has the lowest rolling resistance and best wear. If you plan to drive only in mild weather and on well-maintained roads, straight-rib highway tires at the rear will also give the best mileage and fuel economy. If you will be driving on poorly maintained roads or in harsh weather conditions, use tires with traction patterns or seasonal tires at the rear. 

Special trailer (ST) tires

ST tires are specially built to handle the extra weight of a travel trailer. These tires have a stronger sidewall than other car or truck tires.

Light truck (LT) tires

LT tires are made for vehicles that weigh significantly more than a small pickup truck. As mentioned, these tires are made for class A, B, and C rigs. Costs can vary per class because of weight differences, and heftier RVs are going to need beefier tires.

Radial Tires vs. Bias Tires

Now you’re ready for the next decision—radial or bias tires? Both LT and ST offer each of the two options, so let’s go over a few differences and the pros and cons of each.

Radial Tires

A radial (or radial-ply) tire has its steel belts (cord plies) run at a 90-degree angle to the direction your vehicle is traveling. The radial-ply belt construction is what gives your radial sidewalls that slightly bulging look. It also makes your tire more durable, extends its life, and gives you better fuel economy.

A radial tire’s ability to provide a softer ride makes it the best option for RV drivers who want to take longer trips or plan to use their RVs often. However, they’re often more expensive.

Bias Tires

Bias (or bias-ply) tires are less expensive, but they typically have a shorter lifespan. Their belt construction consists of nylon belts that run at a 30- to a 45-degree angle. This makes their sidewalls stronger and more capable of handling significant weight loads than radial tires. This greater strength reduces the flexing ability of the tire, meaning it has a shorter lifespan than a radial tire.

Without the flexible sidewall, a bias tire’s average lifespan is around 12,000 miles, where you can expect a radial tire to last upwards of 40,000 miles. In other words, a bias tire is better at handling the pressure of heavier loads, but you’ll need to replace it more often than a radial.

Due to their higher weight carrying capabilities, RV owners who tow large fifth wheels or trailers may opt for bias tires, especially when taking short trips or adventuring on rough back roads.

What to Expect When Buying RV Tires

Generally, prices for a good tire can run from around $100 per tire all the way up to almost $600 per tire for Class A, B, and C motorhomes, depending on the size. If you’re pulling a travel trailer, prices are lower, running from $60 to $200 per tire. 

Tires are available to purchase at many large name retailers, like Walmart, Sam’s Club, and Camping World; truck tire dealers; and RV rallies. Expect to see familiar brand names like Bridgestone and Goodyear, as well as brands that specialize in RV tires like Carlisle and Continental.