What is tongue weight?
While your tow vehicle may be capable of towing thousands of pounds, your trailer hitch may not be. Hitches have their own capacity rating. Your trailer hitch and tow vehicle towing capacity limits may not be the same. In cases like this, make sure you don't exceed the lower of the two ratings.
Another consideration for your trailer hitch is its tongue weight. This is the maximum weight your trailer hitch can handle of the downward force exerted on it by the trailer's tongue (the arm that extends from the trailer that couples with the tow vehicle's receiver). A properly loaded trailer should have 60 percent of the weight piled in front of the axle. An unhitched trailer should lean forward, with its tongue touching the ground. The gravitational force that pushed the trailer downward still exists after the trailer is hitched to a tow vehicle.
The tongue weight rating is always less than the weight carrying or distributing capacities; the tongue weight rating should generally be less than 10 percent of the gross trailer weight [source: U-Haul]. While the tongue weight rating of a hitch remains constant (it should be engraved on your tow vehicle's hitch), the actual tongue weight varies by load. You can weigh your loaded trailer's tongue to determine the actual tongue weight; but it's also easy to see if it's too light or too heavy.
A trailer with a proper tongue weight will form a straight line from front to back between the tow vehicle and the trailer. A trailer with the weight improperly distributed (and hence a light tongue weight) will cause the coupling between the coach and trailer to rise, with the weight pressing downward at the rear of the trailer and the front of the coach. Too much tongue weight will do just the opposite. If you notice a rise or fall in your tow coupling, you'll need to redistribute the weight of the load before hitting the road.
Now that you know your tow vehicle and your trailer hitch have limits, you can be safe out there when towing. As long as you never exceed your towing capacities, you can tow confidently. For more information on towing, visit the next page.