Trailers are your reliable workhorse, able to help you transport furniture during a move, drag a camper for a weekend getaway, or transport heavy equipment for work. So, do you know how much poundage your trailer can handle? The answer is not just number—trailer weight rating is your guide to safe towing practices because exceeding it can lead to accidents, damage to your vehicle, and cause potential harm to yourself and others. In this guide, the ARK team unravels the complexities of trailer weight ratings to give you a clear understanding of what these ratings mean, why they matter, and how to determine your trailer axle weight limit.
Classes of Trailer Weight Ratings
Understanding the types of trailer weight ratings is fundamental for safe towing practices. Staying within the load limits will ensure a safe and secure ride while minimizing the risk of accidents or mechanical failures.
Gross Vehicle Weight Rating (GVWR)
The GVWR is the maximum weight a fully loaded trailer can safely carry, including its cargo, equipment, and accessories. It's determined by the trailer's design, construction, tires, and suspension system.
Exceeding the GVWR can strain the trailer's components, including the frame, suspension, and tires, leading to mechanical failures or driver control issues.
Gross Axle Weight Rating (GAWR)
The GAWR specifies the maximum total combined weight of the vehicle and the trailer that each axle can support. It ensures appropriate weight distribution across the axles and prevents overloading, which can lead to premature tire wear, suspension damage, or axle failure.
Accurate weight distribution is essential for towing stability and safety. Exceeding the trailer axle weight limit can affect braking performance and steering control.
Trailer Tongue Weight
Trailer tongue weight is the downward force exerted by the tongue or coupler on the hitch ball. Insufficient tongue weight may cause the trailer to drift or fishtail, especially at high speeds or in windy conditions. Conversely, excessive tongue weight can overload the rear axle of the towing vehicle, affecting its handling and braking ability.
Factors Affecting Trailer Weight Ratings
The weight rating of your trailer is not a fixed number. It's influenced by many factors, from the weight of the load to the road and weather conditions. There is a lot to consider before calculating the weight limit of your trailer. The most important factors include the following:
- Payload capacity. It describes how much poundage your trailer can carry safely. It's determined by the trailer's design, construction materials, and suspension system. However, different types of cargo exert varying amounts of stress on the trailer. For example, transporting lightweight furniture may not strain the trailer in the same way as moving cement bags and heavy construction materials to the job site.
- Towing vehicle's capacity. Your vehicle's towing capacity should match or exceed the trailer weight ratings. Otherwise, it can strain the vehicle's engine, transmission, brakes, and suspension components, causing poor performance, increased wear, and potential safety risks while towing.
- Terrain and driving conditions. Towing on steep inclines or declines can increase the trailer's weight, affecting its performance and stability. Similarly, navigating sharp curves requires careful maneuvering to prevent trailer sway or loss of control. Strong winds, rain, snow, or ice will likely complicate towing and increase the risk of accidents. So be vigilant when towing in rough conditions.
How to Determine Your Trailer's Weight Ratings
Figuring out your trailer's weight ratings doesn't have to be a guessing game. Start by checking the manufacturer's manual or documentation. It should contain detailed information about your trailer weight ratings, including GVWR, GAWR, and tongue weight limits.
Many trailers also have VIN data plates, labels, or stickers attached, clearly displaying the GVWR and GAWR weight ratings. Check near the trailer's hitch or on the frame.
Weigh Your Trailer
If you've modified your trailer in any way, consider taking it to a certified weigh station. These facilities can accurately measure the weight of your trailer, including axle loads and tongue weight.
Alternatively, you can use a specialized trailer scale or load cell to weigh your trailer. These tools are designed to provide precise weight measurements and can be used at home or in a workshop.
Single Axle Trailer Weight Limits
Single-axle trailers are commonly used for light to medium-duty hauling, such as transporting small boats, landscaping equipment, or household items. They have one set of wheels and one axle. Depending on the size, construction, and intended use, a single-axle trailer's weight rating typically ranges from 1,000 to 3,500 pounds. Consider the following:
- Trailer construction: The materials and methods used in building the trailer can affect its weight limit. Heavy-duty trailers made of steel often have higher weight capacities than lighter aluminum trailers.
- Trailer size: The trailer's length, width, and height can impact its weight limit. Larger trailers typically have higher weight capacities than smaller ones.
- Axle and suspension: These components play a crucial role in supporting and distributing the combined trailer and cargo weight. Upgrading to a heavier-duty axle or suspension can increase the trailer's weight capacity.
- Tire rating: The load rating of the trailer tires should match or exceed the trailer's weight limit to ensure safe operation.
Double Axle Trailer Weight Limits
Double-axle trailers offer increased stability and weight capacity compared to single-axle trailers. They feature two sets of wheels and axles, providing better weight distribution. For example, while a single-axle trailer might have a maximum weight rating of 3,500 lb, a double-axle trailer of similar size and construction could have a combined weight rating of 7,000 lb or more.
To determine the double-axle trailer weight rating, check the weight limit for each axle and the maximum load capacity per tire. The combined weight rating determines the overall weight capacity of your trailer.
Measure the Trailer Axle Tube's Diameter
Using a measuring tape, calculate the diameter of your axle tube (its thickness). Refer to the trailer axle capacity chart below to determine the relationship between diameter and trailer weight limit:
| Trailer Capacity | Axle Diameter (Inches) |
|---|---|
Determine the Trailer Weight Rating by Wheel Bearings
The wheel bearings can also indicate your trailer axle weight limit. Common inner and outer bearing numbers correspond to specific axle sizes. Refer to the bearing numbers stamped on the bearings themselves or use a digital caliper to measure them.
| Common Inner Bearings | Common Outer Bearings | Common Capacity - (lb) |
|---|---|---|
L44643 L68149 |
L44643 |
|
15123 LM67048 |
||
15123 02475 |
||
3955 |
387A 3955 |
Consult Experts for Help Determining Your Trailer Weight Limit
If you're still unsure how much weight your trailer can hold, always reach out to our expert team at ARK Corporation. We can provide guidance based on your information and help you accurately determine your trailer weight capacity. Our team offers expert knowledge of all trailers and accessories, including trailer jacks, portable lighting, and more. Here at ARK, we’d rather you ask us before heading out on the road, unsure of your correct trailer weight, and potentially risking life, injury, or equipment. So call us for all your trailer and towing needs. We’re always here to help!