Too much tongue weight on a trailer overloads the tow vehicle's rear axle, causing the rear to sag, reducing steering/braking control, and making the vehicle unstable and difficult to maneuver, especially when turning or braking, which can lead to tire blowouts or loss of control. It effectively lifts weight off the front wheels, compromising traction and braking for the tow vehicle, potentially leading to dangerous swaying or "porpoising" of the trailer.
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.
As the manufacturer recommends, the combined weights of your tow ball loads should always be less than the towing car's weight and towbar limits. If you exceed the overall weights, your towing might push down the rear axle loadings. This lifts the front axles and severely compromises towing abilities.
A good rule of thumb for an acceptable tongue weight for a trailer is to keep the weight between 9 to 15 percent of the gross trailer weight (GTW). For example, if you tow a 5000-pound trailer, the tongue weight should be approximately 600 pounds.
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. You'll also be unable to control the vehicle properly.
If the trailer has too much tongue weight, it can overload the tow vehicle. This can cause a loss of steering and braking control for the tow vehicle. It also puts too much stress and weight on the tow vehicle's rear axle, leading to the axle or suspension failure if not addressed.
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.
If the tongue weight is too little -- less than 10% of the total trailer weight -- the trailer may tend to sway back and forth. If the tongue weight it too much -- greater than 15% -- your vehicle may become less responsive, especially when turning and braking.
Travel trailer hitch height should match the height of your trailer's coupler to keep both units level. This ensures even weight distribution, safe braking, and smooth towing, no tilt, no sway, no guessing.
The tongue height is important. If the ball is too high, the weight moves more onto the tires of the trailer and can cause sway. It's best to check that the trailer tongue is level and get a raise/drop to match. Weight distribution is the most important factor as you mentioned.
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.
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.
Getting this weight right is critical: too little and your caravan can sway dangerously; too much and you risk overloading your vehicle's rear axle and impairing your steering. Ideally, in Australia, tow ball weight should be about 10% of the caravan's loaded mass.
Common Problems or Mistakes to Avoid
- Incorrect tongue weight: too light causes trailer sway; too heavy overloads the rear axle and reduces steering and braking effectiveness. - Assuming the trailer's empty or nominal weight yields safe tongue weight without measuring after loading and hitching.
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.
Moving the Cargo
If the cargo is loaded near the hitch ball, you'll have a higher tongue weight. However, moving the cargo away from the hitch ball will have less weight on the trailer tongue. That's because when you move the cargo, you're pulling the pressure away or towards the trailer's wheels.
The hitch weight should not exceed the towing capacity of your vehicle. If the hitch weight is too heavy for your vehicle to handle, it can lead to poor handling, reduced braking performance, and increased wear and tear on your vehicle's components.
You want to aim for 20” when measuring from the top of the trailer ball to the ground (with an empty vehicle). Then you will simulate a loaded vehicle (e.g., using two adults sitting towards the rear of your tow vehicle), aiming for somewhere in the 18″ range.
What Is Proper Tongue Weight? For conventional trailers with ball-mounted hitches, proper tongue weight is roughly 10 to 15 percent of the total loaded trailer weight.
Typically trailer tongue weight is 10 to 15 percent of the gross trailer weight. On a 7,000 pound trailer that would be 700 to 1,050 pounds. If you had 100 pounds of stuff in the truck bed behind the rear axle that would take the range up to 800 to 1,150 pounds.
Tongue weight is exactly what it says: the weight of the trailer tongue on the hitch of the tow vehicle. The rule of thumb is that you want a tongue weight equal to 7 percent to 12 percent of the total weight of the (fully loaded with fuel and gear) boat/motor/trailer combo.
If you got your licence from 1 January 1997
You can tow a trailer that weighs up to 3,500kg MAM . This is known as a 'category BE' vehicle.
Stick to 55 MPH
U-Haul officially recommends keeping your speed at or below 55 MPH when towing. While that may seem slow, it's certainly much safer. Trailers make your vehicle heavier and longer, which means slower acceleration, longer stopping distances, and ultimately less room for error.
Increasing towing capacity involves upgrading your vehicle's components like the suspension, brakes, and cooling system, followed by a recertification process. However, these modifications must be compliant with Australian Design Rules (ADR) and approved by an authorised engineer.