2010 Hummer H3 Owner's Manual - Page 258

9-74 Driving and Operating lubricant, belts, cooling system and brake system. It is a good idea to inspect these before and during the trip. Check periodically to see that all hitch nuts and bolts are tight. Leaving After Parking on a Hill 1. Apply and hold the brake pedal while you: ... Weight of the Trailer How heavy can a trailer safely be? Speed, altitude, road grades, outside temperature, special equipment, and the amount of tongue weight the vehicle can carry must be considered. 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. Use the following chart to determine how much a vehicle can weigh, based on the vehicle model and options. start the engine, shift into a gear, and release the parking brake. 2. Let up on the brake pedal. 3. Drive slowly until the trailer is clear of the chocks. 4. Stop and have someone pick up and store the chocks. Engine Cooling When Trailer Towing The cooling system may temporarily overheat during severe operating conditions. See Engine Overheating on page 10‑22. Maintenance When Trailer Towing The vehicle needs service more often when pulling a trailer. See this manual's Maintenance Schedule or Index for more information. Things that are especially important in trailer operation are automatic transmission fluid, engine oil, axle Trailer Towing Three important considerations have to do with weight: ... The weight of the trailer. The weight of the trailer tongue. The total weight on the vehicle's tires.