Whether you're hauling construction equipment, vehicles, or oversized loads, knowing your truck's limits can mean the difference between a successful haul and a dangerous situation. After all, the last thing you want to deal with is a broken-down truck and trailer on the side of the road.

So, how do you determine your vehicle's towing capacity? Better yet, why is knowing the towing capacity necessary? Read on to learn more about how to calculate towing capacity – and the role it plays in your hot shot trucking career.

What Is Towing Capacity?

Towing capacity is the maximum weight your vehicle can safely haul.¹ It’s a critical safety measure that helps prevent accidents, vehicle damage, and potential legal issues.

While automakers provide a general towing capacity figure for their vehicles, you’ll want to know how to calculate your specific towing capacity based on your unique situation. This is especially true for hot shot truckers – who often push their equipment to its limits.

Here are the main factors that affect towing capacity:

• Vehicle construction: Frame strength, engine power, and transmission type.
• Existing load: Cargo, passengers, and equipment in the truck.
• Load distribution: How weight is spread across the vehicle and trailer.

As you determine your towing capacity, always err on the side of caution. The last thing you want to do is risk your load by hauling more than your truck can manage.

Why Does Calculating Your Towing Capacity Matter?

When you’re towing loads of any kind, you need to know your vehicle’s limitations.Overloading a vehicle can lead to serious safety hazards on the road, as well as cause damage to your truck and trailer. Not only that, but overloading can also result in hefty fines from authorities.

Calculating your specific towing capacity can ensure that you are not putting too much strain on your vehicle and risking potential accidents or penalties. Knowing this limit can also help you get more strategic with your trips and make necessary adjustments.

Towing Terms to Know

Before looking at how to calculate your towing capacity, here are the key terms you'll need to know²:

1. Gross Vehicle Weight Rating (GVWR): The maximum weight a vehicle can hold when parked, including its own weight plus cargo and passengers. This will range from Class 1 (6,000 lbs) to Class 8 (33,001 to 80,000 lbs).¹
2. Gross Trailer Weight (GTW): The total weight of the trailer and everything loaded onto it.
3. Gross Combined Vehicle Weight Rating (GCVWR): The maximum allowable weight for both the vehicle and trailer combined, including all cargo and passengers.
4. Gross Axle Weight Rating (GAWR): The maximum weight each axle can support.
5. Tongue Weight: The downward force exerted on the trailer hitch while towing.
6. Curb Weight: The weight of the vehicle with a full tank of gas and all necessary fluids, but without passengers or cargo.
7. Payload: The maximum weight the vehicle can support in the cabin and bed, excluding the weight of the vehicle itself.

How to Calculate Towing Capacity

Understanding your truck's towing capacity is crucial for safe operation. Here's how to calculate it:

Step 1: Determine GCVWR 

Find this in your owner's manual. It's the maximum allowable weight of your fully-loaded vehicle and trailer combined. Your payload, tongue weight, and trailer's weight must not exceed this number.

Step 2: Find the Curb Weight 

This is your vehicle's weight with all necessary fluids but no passengers or cargo. It's usually listed in the owner's manual or on a sticker inside the driver's side door frame.

Step 3: Calculate Towing Capacity 

Subtract the curb weight from the GCVWR.

Towing Capacity = GCVWR - Curb Weight

For example:

• If your truck's GCVWR is 25,000 lbs
• And its curb weight is 8,000 lbs
• Your towing capacity would be 17,000 lbs (25,000 - 8,000)

Payload vs. Towing Capacity: Key Differences

While towing capacity refers to what your truck can pull, payload capacity is about what it can carry. Here's how to calculate payload capacity:

Payload Capacity = GVWR - Curb Weight²

Payload includes passengers, cargo in the truck bed, and any aftermarket additions. The main difference between towing and payload is that towing puts a strain on the engine and transmission, while payload affects the truck's suspension and braking systems. It's important to know both capacities when considering what your truck can handle.

An Example

Let's say you have a heavy-duty pickup truck used for hot shot trucking, and you want to tow a large load. Here's how to calculate the towing capacity while considering payload:

1. Determine GCVWR:
   • Your truck's GCVWR is listed as 25,000 lbs.
2. Find the Curb Weight:
   • The curb weight of your truck (full of gas and all necessary fluids) is 8,000 lbs.
3. Determine Payload:
   • Let's say you have a driver (200 lbs), a passenger (180 lbs), and some tools in the truck bed (300 lbs).
   • Total payload = 200 lbs + 180 lbs + 300 lbs = 680 lbs
4. Calculate Available Towing Capacity:
   • Use the formula: Available Towing Capacity = GCVWR - (Curb Weight + Payload)
   • Available Towing Capacity = 25,000 lbs - (8,000 lbs + 680 lbs) = 16,320 lbs
5. Apply Safety Margin:
   • To ensure safety, it's advisable not to exceed 90% of the calculated towing capacity
   • Safe Towing Capacity = 16,320 lbs × 0.9 = 14,688 lbs

Therefore, considering your payload, your heavy-duty pickup truck can safely tow a load weighing up to 14,688 pounds.

As a rule of thumb, never exceed 90% of your calculated towing capacity.³ This allows for a margin of error and accounts for variables like road conditions and unexpected weight fluctuations.

What Are The Key Types of Towing Equipment?

Knowing your towing capacity is only half the battle – you’ll want to make sure that you’ve invested in the right towing equipment to make sure you keep your rig – and your load – safe on the road. For example, even if your trailer is rated for 5,000 lbs, your vehicle may only have a max of 3,500 – so you’ll want to make sure you have all the right equipment.³

• Trailer Hitch Receiver: Available in various sizes (Class I to V) for different towing needs. Most hot shot truckers will need Class IV or V hitches.
• Ball Mount: Critical for safe towing, available in standard and adjustable types. Most standard mounts include 1¼ “, 2″, 2½” and 3″.⁴ Adjustable mounts can be helpful when dealing with trailers of varying heights.
• Pin and Clip: These secure the hitch receiver and ball mount. Always use high-quality, corrosion-resistant pins and clips.
• Trailer Hitch Ball: Must match the trailer coupler for a secure fit. Keep multiple sizes on hand to accommodate different trailers.
• Wiring Harness: Required by law for trailer lights. Ensure your harness is compatible with both your truck and common trailer types in your area.
• Weight Distribution Hitch: Balances weight between vehicle and trailer axles for a smoother ride. This is especially important for long-distance hot shot hauling.

Tip: Regularly inspect all your towing equipment for wear and tear.⁴ Replace any components that show signs of damage or excessive wear, even if they haven't reached their rated lifespan.

Calculate Towing Capacity, Enhance Your Earning Potential

Knowing your towing capacity is one of the foundational parts of a successful hauling career. Here’s a recap of some key ideas from this guide:

1. Keep detailed records of your vehicle's specifications and towing calculations for quick reference.
2. Stay informed about local and state regulations regarding towing limits and required equipment.
3. Consider joining a professional association for hot shot truckers to stay updated on industry best practices and networking opportunities.

Grow Your Career With ACV Transportation

As you continue to build your hot shot trucking career, why not boost your reputation and experience with a trusted partner? With ACV Transportation, you can access hundreds of car dealerships nationwide that are transporting cars from dealership to dealership.

Sign up for our free load board to tap into this constant stream of hot shot loads – and start creating your own way forward with ACV Transportation.

‍

Sources

1. Reading Truck. "Payload and Towing Capacity Unveiled: What You Need to Know." Reading Truck, 17 May 2024, https://www.readingtruck.com/payload-and-towing-capacity-unveiled-what-you-need-to-know/. Accessed 11 July 2024.
2. Firestone Complete Auto Care. "Truck Payload vs. Towing Capacity: What To Know." Firestone Complete Auto Care, https://www.firestonecompleteautocare.com/blog/driving/truck-payload-vs-towing-capacity-what-to-know/. Accessed 16 July 2024.
3. Nationwide Trailers. "How to Measure Towing Capacity: Complete Guide." Nationwide Trailers, 13 Sept. 2023, https://nationwidetrailers.com/blog/how-to-measure-towing-capacity-complete-guide/. Accessed 11 July 2024.
4. CURT Manufacturing. "Towing Capacity Guide - How to Determine Your Vehicle's Towing Capacity." CURT Manufacturing, https://www.curtmfg.com/towing-capacity. Accessed 11 July 2024.
5. Blue Ox. "Towing Capacity Guide – How is Towing Capacity Calculated?" Blue Ox, 11 Oct. 2022, https://www.blueox.com/towing-capacity-guide-how-is-towing-capacity-calculated/. Accessed 11 July 2024.