2009 Hummer H3T Owner's Manual - Page 225

Driving Your Vehicle • Do not tow a trailer at all during the first 500 miles (800 km) the new vehicle is driven. The engine, axle or other parts could be damaged. 4-43 • Vehicles with an automatic transmissions can tow in D (Drive). Shift the transmission to a lower gear if the transmission shifts too often under heavy loads and/or hilly conditions. For vehicles with a manual transmission, it is better not to use the highest gear. Weight of the Trailer How heavy can a trailer safely be? 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. • Then, during the first 500 miles (800 km) that a trailer is towed, do not drive over 50 mph (80 km/h) and do not make starts at full throttle. This helps the engine and other parts of the vehicle wear in at the heavier loads. • This vehicle has a Hill Start Assist feature, which may be useful when the vehicle is stopped on a grade. See Braking on page 4-3 for more information. Three important considerations have to do with weight: • The weight of the trailer • The weight of the trailer tongue • The weight on the vehicle's tires