You can tell if a trailer is overloaded by physical signs like sagging suspension, uneven tire wear, difficulty braking, and excessive sway, but the definitive way is to weigh the loaded trailer and compare it to the manufacturer's Gross Trailer Weight Rating (GTWR). Overloading strains components, causes poor handling, and is illegal, leading to potential tire blowouts, brake failure, and loss of control.
You'll wanna be on the lookout for: Unresponsive brakes (you're hitting the brakes, but they're just not activating like they should) Loss of/worsening steering (your control over the vehicle isn't as good as it should be) Trailer sway (a little wiggle is ok, but your trailer shouldn't be swinging side to side)
Overloading a trailer increases the risk of traffic accidents. A heavier load can cause the vehicle to become unstable, which can lead to the trailer or even the entire vehicle tipping over.
If too much weight is in the wrong place—too far forward, too far back, or off to one side—it puts stress on the frame, axles, tires, and hitch. It also affects how the trailer handles behind your vehicle. Poor weight distribution can cause swaying, uneven tire wear, and longer stopping distances.
Towing Performance: If the trailer is overloaded, it can put too much strain on your towing vehicle, reducing its performance and fuel efficiency and potentially causing mechanical failure.
The "80 towing rule" is a safety guideline suggesting you should tow no more than 80% of your vehicle's maximum rated towing capacity to provide a buffer for safety, human error, and to reduce stress on your vehicle's components (brakes, transmission, engine). It's a rule of thumb, not a legal requirement, that helps protect your vehicle and allows for unexpected road conditions, ensuring better control and longer life for your truck and its systems.
The 60/40 trailer rule is a crucial guideline for safe towing, stating that 60% of the total cargo weight should be loaded in the front half of the trailer (ahead of the axle centerlines) and 40% in the rear to ensure stability and prevent dangerous trailer sway. This weight distribution creates proper tongue weight (weight on the hitch), preventing the trailer from fishtailing or lifting the tow vehicle's rear wheels, which can lead to loss of control.
Top eight mistakes people make while towing
The ideal tongue weight is between 10-15% of the fully loaded trailer weight. Too much will diminish your vehicle handling, while too little will cause trailer sway.
If your trailer sits too high or low, it shifts weight unpredictably. That affects traction and can increase stopping distances.
Cargo can be added to your trailer up to the maximum weight specified on the placard. Remember, the total weight of your fully loaded trailer can't exceed the listed GVWR.
Take a look at the wheel arches of your vehicle. If they look very different from normal when the car is packed, it's likely that you're overloaded. If you don't have a clear view of your mirrors and you can't see out of the back window, it's likely that you're overloaded.
It's not an issue to leave it hooked up, just make sure you aren't lifting the tow vehicle with the tongue jack to level it. Yes you can leave your trailer hooked up to a truck as long as you like.
Trailers with a gross weight of 3,000 lbs. or more are required to have brakes on ALL WHEELS.
Take the weight of your vehicle by itself and subtract it from the weight of your vehicle with the trailer attached. The difference is the tongue weight of the trailer.
Check Your Vehicle's Tow Rating
Every vehicle has a maximum tow rating set by the manufacturer. Find it inside your owner's manual or on the manufacturer's website. If your loaded trailer weighs more than this number, your trailer is too heavy. No guesswork needed.
At what speeds is trailer sway most likely to occur? Sway risk goes up as you travel faster. Most sway happens above 50 mph, but dangerous sway can happen at lower speeds if conditions are right. Highway speeds increase the effects of crosswinds, turbulence, and bumps, so a stable rig is even more important.
Some of the most common causes of trailer sway include improper weight distribution, speeding, tight turns, steep roads, high-speed driving (even within the speed limit), a larger truck passing, surprise wind gusts or crosswinds, over-correcting when swaying starts, and tires that are improperly inflated.
The 80/20 rule for towing is a safety guideline suggesting you should tow no more than 80% of your vehicle's maximum rated towing capacity, leaving a 20% buffer for safety, varied conditions, and extra cargo like passengers and gear. This prevents overloading, reduces strain on the engine and brakes, improves handling, and minimizes wear and tear, ensuring safer operation and longer vehicle life. It's a crucial practice because real-world conditions (hills, wind, vehicle age) are tougher than ideal factory test conditions, and it helps account for payload (tongue weight, passengers, cargo) that eats into capacity.
Now that you're ready to actually begin loading, remember to follow the 60/40 rule. 60% of the cargo weight should be in front of the trailer's axle and 40% should be behind it. This ensures that the tow vehicle receives enough tongue weight to avoid trailer sway and maintain proper steering control.
Speed Limits for Towing
Common maximum speeds range between 45 and 65 mph. Exceeding 45 mph can increase trailer sway significantly, so it's usually safer to stay slower than the general speed limit for passenger vehicles.
The most weight should be placed in front of the trailer axle. The ideal amount is 60 percent. This leaves 40 percent of the weight that should be placed to the rear of the axle. This will help avoid trailer sway and promote optimal driver control.
If you passed your car driving test on or after 1 January 1997, you are permitted to tow a trailer that weighs up to 3,500kg MAM. This is known as a 'category BE' vehicle. Your driving licence information shows which categories of vehicle you're allowed to drive.