2000 GMC Safari Owner's Manual - Page 213

The Tow/Haul Mode is most effective when the vehicle and trailer combined weight is at least 75% of the Gross Vehicle Weight Rating (GVWR) and the maximum trailer weight rating for the vehicle. See "Gross Vehicle Weight Rating" and "Trailer Weight" in the Index. The Tow/Haul Mode for hauling a heavy trailer is most useful under the following conditions Weight of the Trailer How heavy can a trailer safely be? It depends on how you plan to use your rig. For example, speed, altitude, road grades, outside temperature and how much your vehicle is used to pull a trailer are all important. And, it can also depend on any special equipment that you have on your vehicle. The following chart shows how much your trailer can weigh, based upon your vehicle model and options. Vehicle Two-Wheel Drive Axle Ratio 3.23 3.42 3.73 3.42 3.73 Max. Trailer Wt. 5,100 lbs. (2 315 kg) 5,600 lbs. (2 542 kg) 6,000 lbs. (2 724 kg) 5,300 lbs. (2 406 kg) 5,800 lbs. (2 633 kg) D When driving through hilly terrain at speeds below 55 mph (88 km/h). D When driving in low speed or stop and go traffic below 55 mph (88 km/h). D When driving in parking lots. Use the Tow/Haul Mode instead of the previous recommendation to shift to THIRD (3) gear to improve fuel economy at highway speeds and shift performance at lower speeds. Operating in the Tow/Haul Mode when not pulling a heavy trailer will not cause damage to the vehicle, but you may experience reduced fuel economy and undesirable performance from the engine and transmission. The Tow/Haul Mode should be used only when pulling a heavy trailer. All-Wheel Drive Maximum trailer weight is calculated assuming the driver and one passenger are 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. 4-33