RV weight, towing and systems

Start with the tow vehicle’s payload. Check the RV’s loaded weight and both vehicles’ labels before choosing a floorplan, then work through the power, water and maintenance demands of your trips.

The calculators handle arithmetic. For valves, switches and service procedures, use the guide for the component fitted to your rig.

What the truck has to carry

A tow rating is not a payload allowance. Add a measured 1,100 lb tongue load to a 100 lb hitch, 400 lb of occupants and 200 lb of truck cargo, and this example truck must carry 1,800 lb before any other load is added.

Check that sum against the door label. Axle, receiver and combination limits still apply.

Example truck load: four contributionsExample truck load: four contributions; Trailer tongue: 1,100 lb; Hitch equipment: 100 lb; People: 400 lb; Truck cargo: 200 lbExample truck load: four contributionsTrailer tongue: 1,100 lbHitch equipment: 100 lbPeople: 400 lbTruck cargo: 200 lb

Start with the label on the vehicle

Read the unit’s yellow cargo label. Federal trailer labeling rules include full propane in unloaded weight and count onboard potable water as cargo.

Do not subtract propane twice. Brochure shipping weights may use another basis, so verify the packed trailer on a scale.

The trailer-label and water-allowance rules are in 49 CFR 571.110, S4.3.5 and S9.3.5. Decode GVWR and GAWR with the weight-rating definitions.

Weigh the truck separately as well as coupled. RVSEF’s truck-and-trailer weigh report separates the unhitched vehicle, coupled vehicle and complete trailer so you can see the actual axle loads. An advertised tow maximum cannot supply those measurements.