7 Things You Need to Know About Towing Capacity

It may surprise you that there are seven things you need to know about a topic like towing capacity. But there are many consumers who make the common mistake of underestimating the towing capacity they need to tow items behind their car, truck, or SUV.

For example, when automakers advertise trucks and large SUVs, they list the towing capacity with a single number. Sadly, towing capacity doesn’t work like that. Importantly, figuring out the capacity you need to tow requires a series of calculations, each with its own margins of error.

So, before you determine your towing requirements, you’d be well advised to consider these elements that uniquely apply to your towing situation.

1. Towing Capacity 
2. Max Towing Capacity 
3. Towing Capacity Terminology 
4. How to Calculate Towing Capacity 
5. Learn the Trailer Hitch Classes Available 
6. How to Increase Towing Capacity 
7. Important Tips for Towing 

1. What is Towing Capacity?

Towing capacity is the maximum amount of weight a vehicle can safely tow. But that’s not the only equation. The towing capacity can change based on the weight you plan to load inside the car. Additionally, even the distribution of your interior load is consequential.

Auto manufacturers assign a single number, not simply the trailer’s weight you can pull behind your truck or SUV. Consequently, published towing capacities assume the vehicle is carrying a 150-pound driver and absolutely nothing else. For instance, if you add a second person to the cabin, the towing capacity goes down. Similarly, if you weigh more than 150 pounds, the towing capacity goes down. Likewise, if you add a family of four, a weekend’s worth of gear, and a cooler full of ice and drinks, towing capacity goes way down.

But there are other limits for what you can safely tow, including “tongue weight” (more on that later).

2. What is Max Towing Capacity?

Once again, it’s not wise to assume your vehicle can tow as much as the maximum towing capacity listed in your owner’s manual. On the other hand, towing more than your vehicle is rated for is extraordinarily dangerous.

Here’s What Can Happen if You Exceed Tow Capacity

If you tow weight that is beyond your vehicle’s rated capacity, several unforeseen things can happen, including the below.

• Brake issues. It could reduce the stopping time of your brakes.
• Makes U-turns challenging. Could make an average U-turn nearly impossible.
• Reduces acceleration. It would reduce acceleration, making your vehicle struggle to get up to speed on the highway.
• Increases accidents. Subsequently, each of these scenarios increases your chance of getting into an accident.
• Harms drivetrain. Above all, miscalculating towing capacity may also do expensive damage to your vehicle’s drivetrain.
• Nullifies warranty. In addition, the simple act of towing more weight than the rated capacity violates your truck’s warranty, so repair costs could rise as a result.
• Causes potential fines. It’s also possible to cost you money in the form of fines. It’s illegal to exceed the towing capacity of your vehicle in most jurisdictions, and police have an easy time spotting the overloaded vehicle that can’t get up to speed and ends up sliding through stop signs.

3. Towing Capacity Terms You Need to Know

Meanwhile, in calculating your vehicle’s towing capacity, you might want to familiarize yourself with the various terms and acronyms that define the weight calculations you anticipate.

Gross Vehicle Weight Rating (GVWR)

Gross Vehicle Weight Rating (GVWR) is the maximum amount of weight your vehicle can support while sitting still. It is affected by your car’s frame, wheels, suspension, and axles. A change to any one of those will change the GVWR.

The GVWR is usually found on a sticker inside the driver’s door jamb and in the owner’s manual.

Likewise, a tow vehicle and the trailer it is pulling each have a unique GVWR. What is important is that you don’t overload either.

GVWR is not towing capacity. To clarify, the amount of weight your vehicle can support that pushes down on it, and the amount of weight it can pull behind are two different numbers. For instance, it’s like how the weight you carry on your shoulders is not the same as the amount you can pull in a wagon.

Gross Combined Weight Rating (GCWR)

Gross Combined Vehicle Weight Rating (GCVWR) or Gross Combined Weight Rating (GCWR) is the maximum weight of a tow vehicle and its trailer combined — when they are both loaded with their full cargo.

Because your tow vehicle and trailer each have a unique GVWR, you must add the capacity ratings together to find the GCWR.

Gross Axle Weight Rating (GAWR)

Just as the total amount of weight your car can support matters, so does the distribution weight of the cargo. Therefore, the Gross Axle Weight Rating (GAWR) is the maximum weight that only one axle can support.

In most cases, vehicles use different axles in the front and rear. So, they also have unique GAWR numbers for the front and rear axles.

Gross Trailer Weight (GTW)

Gross Trailer Weight (GTW) is the total weight of your trailer once it is fully loaded. It is not just the empty weight of the trailer. It includes everything you put inside, from water in the tank of a camping trailer to horses in a horse trailer. GTW can never exceed your vehicle’s towing capacity.

If you were to attempt to pull a trailer that weighs more than the manufacturer says your vehicle can tow, you might be able to get it moving. But you’d find it difficult to control and likely be unsafe on the road. You could also damage your car and violate your vehicle’s warranty.

You can determine GTW only by placing the fully loaded trailer on a vehicle scale. If you put the fully loaded trailer on a scale, the resulting measurement would be the GTW. If your GTW exceeds your vehicle’s towing capacity, you will not be able to move it safely. It is crucial that you never even attempt to tow a GTW higher than your towing capacity. While it might be technically possible to carry the load, you’re likely to damage the tow vehicle, the trailer, or both and not control the vehicle properly.

Tongue Weight (TW)

Tongue weight is simply the force of weight pushing down on the trailer hitch itself. Like other weights, it can adjust based on how the load is distributed within the trailer and can also change suddenly while moving if your load shifts.

Curb Weight (CW)

Curb weight signifies the total weight you get after you have loaded all fluids, including a full gas tank, but with no passengers or cargo inside. So, curb weight cannot be used as the weight of your tow vehicle when performing towing calculations because the car won’t be empty when you’re pulling something with it.

Dry Weight (DW)

Dry weight is the total weight of a vehicle without the fluids necessary to operate and with no passengers or cargo inside. Consequently, you don’t need to know your vehicle’s dry weight as part of towing calculations.

Payload

Payload is the total weight of all cargo and passengers in your tow vehicle. On the other hand, it is not the total amount of weight the bed of a truck can carry. Remember, the driver is part of the payload. In addition, passengers are part of the payload. Moreover, anything in the cabin, from a bottle of water to a week’s worth of camping supplies, is also part of the payload.

Braked vs. Unbraked Towing Capacity

Some trailers have integrated brakes. These devices are wired into the tow vehicle’s brakes to activate both brake pedals on the tow vehicle and the trailer. These helpful built-in brakes drastically increase the potential towing capacity. Therefore, braked towing capacity is much higher than unbraked towing capacity.

4. How to Calculate Towing Capacity

Please do not rely on the towing capacity numbers advertised for your vehicle. Because these numbers use a best-case scenario, you are probably not towing under perfect conditions.

To be safe, you need to calculate your vehicle’s towing capacity under the specific conditions you’re in each time you tow.

To do that, you’ll need to know the full GCVWR – the total weight of your tow vehicle and everything in it, combined with the total weight of your trailer and everything in it. Subtract your vehicle’s curb weight from that number to get the towing capacity.

For safety reasons, always leave a margin of error.

A Note on Advertised Towing Capacity

Carmakers often emphasize towing capacity when they advertise trucks and SUVs. The numbers they give can be misleading. They often refer to specially-configured truck models, which may not resemble the typical truck shoppers buy.

The 2022 Chevy Silverado, for instance, is sometimes advertised with a maximum towing capacity of 36,000 pounds. This rating applies only to the Silverado 3500HD with the 6.6-liter Duramax diesel engine, rear-wheel-drive, dual rear wheels, max towing package, and gooseneck hitch.

The more common Silverado 1500 most shoppers buy can tow anywhere from 6,600 pounds to 13,400 pounds depending on which engine, bed, and cab the buyer chooses.

5. Trailer Hitch Classes

The amount of weight your truck or SUV can pull is just one factor in how much you can safely tow. Another is the strength of the tow hitch you have installed.

There are five classes of towing hitches, each with its limits and typical uses. They include:

Class I

Tongue Weight: up to 200 lbs
Towing Capacity: up to 2,000 lbs
Uses: Cargo trays, bicycle racks, personal watercraft

Class II

Tongue Weight: up to 350 lbs
Towing Capacity: up to 3,500 lbs
Uses: Small utility trailers, small boats, small 2-wheel campers

Class III

Tongue Weight: up to 800 lbs
Towing Capacity: up to 5,000 lbs
Uses: Medium utility trailers, medium size campers, and boats

Class IV

Tongue Weight: up to 1,200 lbs
Towing Capacity: up to 10,000 lbs
Uses: Large utility trailers, large campers, and boats

Class V

Tongue Weight: up to 2,000 lbs
Towing Capacity: up to 20,000 lbs
Uses: Horse trailers, multi-car trailers, fifth-wheel campers

See the towing capacity guide at our sister site, Kelley Blue Book, for more information.

6. How to Increase Towing Capacity

The good news is that it is possible to upgrade your vehicle’s towing capacity by upgrading the components that help your vehicle support weight and pull it. But we should caution that there is probably more bad information than good circulating online about how to do so.

Plenty of talented hobbyist mechanics, and more than a few professional shops, misunderstand an essential truth about towing upgrades. Consequently, your vehicle can pull exactly as much as the weakest component in its frame, suspension, and drivetrain allow. Making any one part stronger may not improve your towing capacity at all.

For instance, reinforcing one leg of a table doesn’t mean the table can support more weight. It might just help you break the other three by placing more weight on one leg than it can handle. In the same way, putting more robust struts on your truck might help you break the frame with a heavier weight.

Certain professional services and accessories can improve your vehicle’s towing capacity. The caveat is that the items on the list below must be installed by a knowledgeable pro and balanced with other components.

Upgrade Your Hitch

Moving up a class in hitch is the easiest way to improve your towing capacity. But only if your vehicle can tow the weight that the hitch device can carry.

Add a Weight-Distribution Hitch

A weight distribution hitch uses spring bars to help better distribute the forces a trailer places on your vehicle and prevent a trailer from swaying. It is often the most cost-effective way to upgrade your towing capacity.

Upgrade the Brakes

Larger brake pads and rotors can help your vehicle control a heavier load.

Replace the Axles

Replacing the axle with a beefier device can increase the Gross Axle Weight Rating (GAWR). Some RV shops specialize in this enhancement, which can be necessary to help a truck tow a heavy RV.

Replace the Radiator

Engines work extra hard to pull a heavy load. Upgrading to a larger radiator can help your engine maintain its temperature while towing.

7. Important Tips for Towing

To sum it up, towing is a skill. Just as you practice driving a car to learn motor skills, you need to practice towing a trailer, boat, or camper to learn how to control a longer, heavier vehicle. So, we recommend that drivers start slow with smaller loads and work up to tow a heavy trailer.

First, it’s important to accelerate slowly, to allow extra distance for braking, and to make your turns gently when towing. A trailer can sway and rock as you accelerate, slow, and turn. Above all, towing takes patience and a ginger touch on the controls.

Also, ensure that you know your vehicle’s exact towing capacity before you purchase or rent a trailer to tow, and remember to include yourself, your passengers, and your cargo in the calculations.

Finally, give the tow vehicle and trailer a walk-around before setting out. Ensure that the hitch, security chains, and brake indicator light are correctly attached. Set your mirrors so that you can see the trailer as well as what’s behind it.