The tongue of the boat trailer is the point where it hooks up to the hitch on the car. The length of the tongue is necessary to give some distance between the bow of the boat and the towing vehicle.
The tongue of the trailer presses down on the trailer hitch, and that is tongue weight. How hard it presses down is a function of the weight in front of the trailer wheels, and how much of the weight is not offset by the weight behind the wheels. If the tongue weight is too great, the rear of the towing vehicle goes down. Too light, and the boat trailer will swing side to side.
Fuel has weight. Depending on the location of the tanks, it can shift the balance of weight, increasing or decreasing how hard the tongue of the trailer presses on the hitch. Too far in either direction could make it unsafe to tow the boat/trailer.
I tow my boat with a tongue weight of about 140 pounds and a tow weight of 1500 pounds and the truch handles ok but the bumper has started to sag at the hitch
5 to 10 percent %
5 to 10 percent %
5 to 15
5 to 15%
5 to 15%
5 to 15%
5 to 15%
5 to 15%