Why It’s Important to Know Your RV Tire Load Range & RV Weights (2024)

Knowing (and staying within) the limits of your RV tire load range is critical to your safety and that of your family as you travel. But what exactly does tire load range mean and why is this information so important? And if you’re replacing your tires, what load range tire do you need for your RV?

In this post, we’re dropping some incredibly important (but often overlooked) information about your RV or trailer tires that could be the difference between traveling safely… or not.

What Does Tire Load Range Mean?

The term “load range” is technically based on the tire’s ply rating. The load range combined with the tire size tells you the tire’s load capacity, including how much weight and air a particular tire is rated to hold. A tire’s load range is often noted alphabetically and should be found stamped on the sidewall as a single letter (A, B, C, D, E, F, G, or H), usually right after the tire size. The correct tire load range can also be found in the owner’s manual of your trailer.

In general, the higher the load range, the heavier the load the tire can carry. If you are comparing two tires of the same size, one with a load range of B, and the other with a load range of D, the D-range tire will have a higher weight capacity.

The load range code of trailer tires generally ranges from B to F. These codes relate to the tire’s ply rating as follows:

• B = 4-ply rating
• C = 6-ply rating
• D = 8-ply rating
• E = 10-ply rating
• F = 12-ply rating

However, a tire rated “F”, for example, doesn’t necessarily have 12 plies. It simply means that the tire has the equivalent strength of 12 plies (as tire and rubber technology has changed over the years, the nomenclature for load ratings has stayed the same). The tire’s load range gives you an idea of how much air the tire can hold, how much weight it can carry, and how durable it is when compared with other tires.

One complication with load range is that it doesn’t, by itself, indicate the load-bearing capacity of any tire. Since tires of different sizes can have the same load range (or ply rating equivalent), you also need to know the tire’s size to be able to determine how much weight it can carry.

Load Range vs Load Index: What’s The Difference?

A tire’s load range is based on its ply rating (or ply rating equivalent) and is a somewhat older way to measure tire carrying capacity. The load index correlates to a tire’s maximum safe carrying capacity when inflated to its maximum pressure. Load index is a numerical system, while load range is an alphabetical system.

Both tell you a tire’s maximum carrying capacity, but the load range (based largely on ply rating) is an older rating system. Some tire manufacturers have begun using load index (the more modern, numerical system) to indicate a tire’s maximum load-carrying capacity.

The reason we’re seeing a switch to load index as an expression of a tire’s weight or load-carrying capacity is that the ply rating of tires no longer directly correlates to the number of plies used in a tire’s construction due to advancements in tire technology.

The most important thing to know about load range is that a tire’s load range combined with the tire size tells you that tire’s load capacity.

What Load Range Should My Trailer Tires Be?

The weight rating associated with a tire’s load range is per tire. For example, if your tire has a 2,000-lb rating, then with two of them on a single axle, the tires can support up to 4,000 lbs total.

As a general rule of thumb, your trailer tire’s rated load capacity should be at least 20% greater in capacity than the weight of your trailer.

So, if your single-axle trailer weighs 4,000 lbs, you could ideally have 2,000 lbs at each wheel position (though it would be best to get individual corner weights if possible, since the weight in your trailer may not be evenly distributed to each wheel position). Since 20% of 2,000 lbs is 400 lbs, you’d want a trailer tire with a load range that covers at least 2,400 lbs.

The load range for your trailer tires will be stamped into the sidewall along with the maximum allowable load (usually in pounds and kilograms) for both single-tire axles (one tire per side of the axle) and double/dual-tire axles (two tires at each end/side of the axle).

Note: The double/dual tire rating is usually lower per tire than the single tire rating. This is because the sidewalls of the tires flex outward as weight is put onto them. This flexing means that in a dual-tire application, the tires could touch/rub, leading to premature failure.

Again, the correct tire load range can also be found in the owner’s manual of your trailer.

5 Tips to Keep In Mind When Replacing Your RV/Trailer Tires

The following are the most important considerations to keep in mind when replacing your RV/trailer tires:

Specific Size and Load Range

Your RV/trailer’s owner’s manual will indicate the appropriate size and load range of its tires. You should always replace your RV/trailer’s tires with tires of the same size and (at least the same) load range.

NOTE: If you aren’t the first owner of the RV, it’s a good idea to check the owner’s manual (or contact your RV’s manufacturer) to be sure you replace the current tires with the correct size and rating. A previous owner MAY have installed undersized/rated tires due to a lack of availability or knowledge.

All Tires Must Be the Same Size

All of the tires on your RV or trailer must be the same size to manage the weight of the RV/trailer properly. Load ranges/indexes can be mixed (although you should never drop below the manufacturer’s recommended range), as long as the other dimensions/specs of the tire match (like size, diameter, etc).

Keep Tires at Maximum PSI

Remember that a tire’s load range is the maximum weight load it can handle at its fully rated air pressure. As we’ve noted in our post on why RV tires blow out (and how to prevent tire blowouts), the number one reason for a tire blowout is an underinflated tire. Keeping your RV’s tires properly inflated is of paramount importance.

This is why we always keep a high-quality Viair RV air compressor on board like this one:

VIAIR 400P-RV Compressor

You can also get the latest upgraded RVS model of the Viair air compressor (with our RVgeeks discounts) through TechnoRV and MobileMustHave.com:

You should also know what cold tire pressure is and why it matters, as well as what to do (and what NOT to do) if you have a tire blowout. We encourage you to also see our post on how long RV tires last and what affects their lifespan.

Tires Must Meet or Exceed the Recommended Load Range

When you replace your RV’s or trailer’s tires, the load range should always meet or exceed the recommendation on the door placard or in your owner’s manual. It can be higher than the recommended load range, but never lower. Keep in mind, however, that going to a higher-capacity tire does not increase the capacity of the trailer. Other components like the axles, brakes, and suspension also limit the maximum weight your trailer can be.

A Safety Margin Is Important

As we noted above, it’s a good idea for your trailer tire’s rated load capacity to be at least 20% greater in capacity than the gross vehicle weight rating (GVWR) of your trailer. For example, if a fully loaded tandem axle trailer weighs 4000 lbs, each of its four tires will bear one-quarter of that load, which is 1,000 lbs each. So, a tire rated for at least 1,200 lbs (20% more than the 1,000 lb weight at each tire position) will provide a good safety margin.

Finally, because RV tire pressure is so critical, we suggest reading our post on RV tire pressure. And as always, keep our tire safety tips in mind.

NOTE: Subscribers to our daily newsletter also receive access to our free eBook all about RV tire pressures (it’s a link inside the welcome email you receive once you subscribe). Use the following form to subscribe if you haven’t already (and existing subscribers can re-enter the same email they’re already subscribed with to receive a new “Welcome Email” with the eBook link).

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