2010 Cadillac STS Owner's Manual - Page 351

Three important considerations have to do with weight: ... Weight of the Trailer Tongue The tongue load (A) of any trailer is an important weight to measure because it affects the total gross weight of the vehicle. The Gross Vehicle Weight (GVW) includes the curb weight of the vehicle, any cargo carried in it, and the people who will be riding in the vehicle. If there are a lot of options, equipment, passengers or cargo in the vehicle, it will reduce the tongue weight the vehicle can carry, which will also reduce the trailer weight the vehicle can tow. If towing a trailer, the tongue load must be added to the GVW because the vehicle will be carrying that weight, too. See Loading the Vehicle on page 5‑23 for more information about the vehicle's maximum load capacity. The weight of the trailer. The weight of the trailer tongue. The total weight on the vehicle's tires. Weight of the Trailer How heavy can a trailer safely be? It should never weigh more than 1,000 lbs (450 kg). But even that can be too heavy. It depends on how the rig is used. For example, speed, altitude, road grades, outside temperature and how much the vehicle is used to pull a trailer are all important. It can depend on any special equipment on the vehicle, and the amount of tongue weight the vehicle can carry. See "Weight of the Trailer Tongue" later in this section for more information. Maximum trailer weight is calculated assuming only the driver is in the tow vehicle and it has all the required trailering equipment. The weight of additional optional equipment, passengers and cargo in the tow vehicle must be subtracted from the maximum trailer weight. Ask your dealer/retailer for our trailering information or advice, or write us at our Customer Assistance Offices. See Customer Assistance Offices on page 8‑6 for more information. If using a weight-carrying hitch, the trailer tongue (A) should weigh 10 to 15 percent of the total loaded trailer weight (B). 5-33