Understanding Trailer Gross Tongue Weight
So, there is something new outside the house. It sits on the street, in the driveway, or on a specially constructed pad. The trailer is bright with wax, brilliant in color, and the new pride and joy of the family. A twinkle is in your eye and smiles on the faces of your family as they imagine the joys of traveling the road across the country or the county. But, wait a minute, looking over your owner’s manual, there is a small item called “Gross Tongue Weight (GTW).” Now, one may ask, what the heck is the GTW and how important is it?
The answer to that question is that the GTW is the amount of pressure placed on the hitch when the trailer is sitting still on an even plane by a combination of the weight from the trailer and whatever burden is placed behind the rear axle of the tow vehicle. GTW is a vital lever point where pressures are equalized. Yeah, a bunch of technical jargon that does not make sense to the average reader. Just know that if those pressures are left unattended and do not equal out, then there is an issue that is dangerous to everyone involved.
What is GTW?
We know that the term sounds a bit technical, but the GTW rating is based on tests that imitate the added forces generated by the bumps, holes, and other deformities found on the roads of America. The connection is tested through a series of braking force tests on a downward plane, and upward, plane, and on a level road. The impact of the forces created by wind tunnels, passing large trucks, and grapevine turns are also simulated. After all this testing, the GTW is established.
How is GTW Exceeded?
When that new trailer arrives, it is a balanced unit that meets the limits of the GTW rating. But, when you add your food, personal items, extra camping equipment, water, and so on, you disrupt the weight pattern established in the factory where the trailer was carefully constructed.
If the GTW is exceeded, the stability of both the trailer and the tow vehicle is compromised. The effect is to raise the front of the tow vehicle, limiting steering and braking control. To avoid this situation, we advise that you measure your tongue weight each day.
How to Find Tongue Weight
There are several methods of measuring tongue weight. One of those is not to pick up the trailer by the tongue and judge it through the power of your shoulders unless you happen to be Hercules or some other Ancient Greek god. Here is a list of possible methods from the least effective to the most effective:
- Bathroom Scale
- Tongue weight measuring tool
- Built in tongue weight scale
- Commercial weight scale
Let’s look at each of these so that we know the limitations and benefits of each.
Visualization is the least effective method of how to find tongue weight. Drivers towing a vehicle should only use it in an emergency, and as a temporary judgment call that they cure as quickly as possible with more accurate methods of tongue weight measurement.
The method of visualization is simple. Attach the trailer to the towing vehicle via the hitch. Move to a level area, park, and get out to observe the connection between the trailer and tow vehicle. You should take ten steps back and squat. Look at the connecting point. If the trailer is over its recommended GTW, then there will be a slight dip at the connection point. If the trailer is packed too heavily in the rear, then you will notice a small lift at the connection point.
If you do not notice any lift or dip, then your tongue weight is probably within correct limits. You are temporarily safe to “Ease on down, ease on down, the road, yeah, yeah, yeah.” Just remember to stop at your first opportunity to find an accurate tongue weight measurement.
4. Bathroom Scales
We recommend the use of bathroom scales to measure the tongue weight for smaller trailers. After all, most bathroom scales top out at 300-350 pounds. To properly measure the tongue weight of your trailer you will need the find these pieces of material and pack them inside your trailer every morning. You will need to carry these extra items:
- Bathroom scale
- A brick
- Two three-foot lengths of pipe
- One 2” x 4” piece of lumber cut to a five-foot length
To establish your tongue weight with a bathroom scale, use the following process:
- Find a level location like a parking lot to make your weigh
- Place the brick and scale three-foot apart on a level plane beneath the ball hitch of your vehicle
- Lay the pipes to connect the scale and the brick
- Place the 2” by 4” lumber across the pipes one foot from the brick and two foot from the scale to set up a three-to-one weight ratio
- Assure yourself that the platform is at the same level as your hitch socket
- Lower the tongue jack and detach the towing vehicle from the trailer
- Slide the bathroom scale and accompanying material under the tongue
- Raise the jack to lower the tongue onto the wood and get the weight
- Multiply the weight by three to get the true tongue weight
Though we recommend this measurement process over the use of visualization, we urge you to obtain a tongue weight measuring device to get a more accurate reading with a simpler process.
3. Tongue Weight Measuring Tool
Using the bathroom scale method to find your tongue weight every morning is a difficult process that takes up cargo room. A tongue weight measuring tool is a much better method of getting an accurate measurement of your tongue weight. The steps to using these compact measuring devices are simple:
- Park you tow vehicle and trailer on a hard and level surface
- Place the scale beneath the tongue jack
- Crank the tongue jack down until it sits firmly on the scale
- Detach the trailer from the tow vehicle
- Take the reading
You can shorten the process further by purchasing a built-in tongue weight scale.
2. Built-in Tongue Weight Scale
The built-in tongue weight scale comes with an expense. Though the unit costs more than a traditional tong weight scale, its convenience makes up for the difference quickly for those drivers making long trips, say, from Philadelphia to Alaska. The built-in tongue weight is a part of the ball joint. The unit has a mini-scale inside the ball joint that constantly weighs the tongue. To activate it, you attach your trailer to your ball hook. It is as easy as that. But, every surface of a parking lot or road has the bumps, dips, and angle deviations that are unobservable to the naked eye. The only place you will get a true measurement is at a commercial weigh station.
1. Commercial Weigh Station
Commercial weight stations are designed and constructed to present a level surface. To find your tongue weight:
- Drive your towing vehicle on to the scale pad with the trailer attached
- make sure all four tires of your tow vehicle are on the pad, but the trailer sits off the pad
- Take the weight from the attendant
- Detach the trailer from the tow vehicle
- Get the weight from the attendant
- Subtract the unattached weight from the attached weight to get your tongue weight
If you think you are close to the maximum on your GTW rating, then you should use a private commercial scale for an accurate reading. They charge a fee, but that fee is less than the fine you will get at a public weigh station if you are overweight. Always check your tongue weight for a joyous journey with your family to places you have only imagined. Go, have a great time, and enjoy that new shiny object as a traveling home that creates memories of places seen, adventures made, and family experiences. Hook up, measure, and ease on down that road.