Before you head out on the open road with your trailer or other tow load, make sure that you are not exceeding your vehicle's maximum towing capacity. You should never exceed the maximum towing weight. It is a good idea to leave a 20 per cent safety margin.
Look on the door panel of your vehicle for a tab that lists the gross combination weight rating, or GCWR, which is the maximum weight that your vehicle plus your tow load should weigh. This number includes everything inside your vehicle. The number will also be in the owner's manual.
Find the gross vehicle weight, or GVW, which is the total weight of your vehicle including everything inside your vehicle. You can weigh your vehicle on weigh scales typically found at truck stops.
Subtract the GVW found in Step 2 from the GCWR found in Step 1. GCWR - GVW = Maximum Trailer Weight. The answer of this equation will equal the maximum weight your vehicle can tow. Although you might know the weight of your trailer, you can never be completely sure of your tow load unless you take your fully loaded trailer to a weigh scale.