2007 Buick LaCrosse Owner's Manual - Page 330

Weight of the Trailer Tongue The tongue load (A) of any trailer is an important weight to measure because it affects the total or gross weight of the vehicle. The Gross Vehicle Weight (GVW) includes the curb weight of the vehicle, any cargo 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. And if you tow a trailer, you must add the tongue load to the GVW because the vehicle will be carrying that weight, too. See Loading Your Vehicle on page 319 for more information about the vehicle's maximum load capacity. When using a weight-carrying hitch, the trailer tongue (A) should weigh 10 percent to 15 percent of the total loaded trailer weight (B). After the trailer is loaded, weigh the trailer and the tongue, separately, to see if the weights are proper. The correct weight could be achieved simply by moving some items around in the trailer. 330