2003 GMC Sonoma Owner's Manual - Page 256

If yours was built with trailering options, as many are, it's ready for heavier trailers. But trailering is different than just driving your vehicle by itself. Trailering means changes in handling, durability and fuel economy. Successful, safe trailering takes correct equipment, and it has to be used properly. That's the reason for this part. In it are many time-tested, important trailering tips and safety rules. Many of these are important for your safety and that of your passengers. So please read this section carefully before you pull a trailer. Then, during the first 500 miles (800 km) that you tow a trailer, don't drive over 50 mph (80 km/h) and don't make starts at full throttle. This helps your engine and other parts of your vehicle wear in at the heavier loads. You may want to shift the transmission to THIRD (3) or, if necessary, a lower gear selection if the transmission shifts too often (e.g., under heavy loads and/or hilly conditions). If you have a manual transmission and you are towing a trailer, it's better not to use the highest gear. Three important considerations have to do with weight: @ If You Do Decide To Pull A Trailer If you do, here are some important points: 0 the weight of the trailer, the weight of the trailer tongue and the weight on your vehicle's tires. There are many different laws, including speed limit restrictions, having to do with trailering. Make sure your rig will be legal, not only where you live but also where you'll be driving. A good source for this information can be state or provincial police. Consider using a sway control if your trailer will weigh 3,500 Ibs. (1 589 kg). You should always use a sway control if your trailer will weigh more than 3,500 Ibs. (1 589 kg). You can ask a hitch dealer about sway controls. Don't tow a trailer at all during the first 500 miles (800 km) your new vehicle is driven. Your engine, axle or other parts could be damaged. 0 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. 4-55 0 e