What is Tongue Weight?
Tongue weight is also called hitch weight or tongue load.
Tongue Weight refers to the downward pressure exerted on the tow ball by the “tongue” at the front of the tow vehicle. When a trailer is connected to your vehicle, some of the weight is distributed to the connection between the vehicle and the trailer (the tow bar). The normal tongue weight can keep the chassis of the trailer on a horizontal line, ensuring the safety of the tractor while driving.
When towing a trailer, the entire weight of the trailer is not considered part of the overall weight of the car, rather the tongue weight is part of the overall weight of the car. When calculating the total mass of the train, we also need to include the weight of the tongue into the total mass.
During the towing process, Tongue Weight is an important force to maintain the stability of the front and rear vehicles and ensure a safe journey. However, many RV enthusiasts or owners preparing to purchase an RV do not realize its importance.
What is the appropriate tongue weight?
Trailer and vehicle manufacturers conduct extensive testing to determine the optimal tongue weight for their specific models. Over time, the recommendation that the downward force of the trailer on the hitch ball should be approximately 10-15% of gross trailer weight(GTW) is a result of this testing and is considered a practical and safe range for a wide variety of towing situations.
While the 10-15% guideline is a general recommendation, it’s essential to check the specific recommendations provided by the vehicle and trailer manufacturers. Optimum Tongue Weight may vary depending on trailer type and intended use.
For gooseneck trailers and fifth-wheel trailers designed to handle larger loads, a suitable drawbar weight is 15 to 30 percent of the trailer’s load weight.
What will happen if the tongue weight is too heavy?
Higher tongue weight will increase the pressure on the tow vehicle and lift the rear of the trailer. This can affect the balance of the vehicle, especially when trying to turn or negotiate curves, making maneuvering extremely difficult and causing oversteer.
Excess tongue weight will put extra burden on the rear braking system of your vehicle. Especially when going down steep slopes, it may cause premature wear of the brake system and reduce braking efficiency.
What will happen if the tongue weight is too low?
Too low tongue weight will cause the rear axle to be overloaded and the trailer’s rear end to sink. This can cause the trailer to easily oscillate or swing from side to side, especially at higher speeds or in windy conditions. The towing vehicle may have difficulty controlling the rocking motion, making the entire towing unit unstable.
A too low tongue weight is more dangerous than a too heavy tongue weight
Too much tongue weight contributes to oversteer, but it may enhance the effectiveness of the tow vehicle’s brakes, as there is more weight on the rear tires. Oversteer is a handling issue, it tends to be more predictable and manageable compared to the unpredictable nature of trailer sway resulting from too little tongue weight.
So, proper tongue weight ensures that the rear tires of the tow vehicle maintain good traction on the road. This is important for both steering and braking control.
When the tongue weight is too heavy or too low, it may cause uneven wear of the rear wheels of the trailer vehicle. This means changing tires more frequently; and possibly suffering a puncture while traveling. When the front and rear of the trailer are unbalanced, the front wheels will lose traction. This will disrupt the balance of the vehicle in slippery or complex road conditions, and can easily cause the front and rear vehicles to slide sideways or lose control.
The normal tongue weight can keep the chassis of the trailer on a horizontal line, ensuring the safety of the tractor while driving. Too heavy or too low tongue weight will cause the front and rear ends of the trailer to rise or sink. This state not only affects the safety during driving, but also reduces the height of the chassis, thus affecting the driving passability. Of course this also goes hand in hand with the loading of your trailer.
As we just mentioned, a low tongue weight is more dangerous than a heavy tongue weight. The weight of the trailer is more dangerous when it is concentrated in the rear than in the front.
How should heavy objects be placed?
We should place heavy items under the trailer and close to the axle, and place other objects evenly to ensure that the overall center of gravity is at the axle and close to the ground, so that the entire trailer is more stable.
Make sure the tongue weight matches the calculated value
When towing a trailer with a towing vehicle, you need to determine the total mass of your trailer and then calculate the range of tongue weight. After the towing is completed, you need to check the tongue weight value displayed on the trailer device. If it is not within the calculation range, we can move the trailer’s items front and rear to adjust it.
For example, if your GTW is 500kg, the tongue weight should be 10-15% of it, and the calculated value is 50kg-75kg. When the tongue weight is less than 50kg, you can move the items in the trailer slightly toward the front of the trailer until the tongue weight is displayed between 50kg and 75kg. On the contrary, when the tongue weight is larger than 75kg, you can move the items in the trailer back slightly until the tongue weight is displayed between 50kg and 75kg.
What should you do if the towing device cannot directly read the tongue weight value of the tow bar?
If your towing device cannot directly read the tongue weight value of the tow bar. According to what we said before, after the trailer is towed, the actual weight of the towing vehicle is the load plus tongue weight. The towing vehicle first drives to the portable axle scale for weighing and obtains the weight value A.
Then drive down the towing vehicle, tow the trailer onto the towing vehicle, and then drive the towing vehicle onto the weighing platform (do not pull the wheels of the trailer onto the scale) to obtain the weight value B at this time.
The value obtained by reading B-A is the value of tongue weight.