2003 GMC Sierra 1500 Pickup Owner's Manual - Page 326

0 Coasting downhill in NEUTRA N) or with the ignition off is dangerous. Your brakes will have to do all the work of slowing down. They couldget so hot that they wouldn'twork well. You would then have poor braking or even none going down a hill. You could crash. Always have your enginerunning and your vehicle in gear when you go downhill. Know how to go uphill. You may want to shift down to a lower gear. The lower gears help cool your engine and transmission, and you can climb the hill better. Stay in your own lane when driving on two-lane roads in hills or mountains. Don't swing wide or cut across the center of the road. Drive at speeds that let you stay in your own lane. As you go over the top of a hill, be alert. There could be something in your lane, like a stalled car or an accident. You may see highway signs on mountains that warn of special problems. Examples are long grades, passing or no-passing zones, a falling rocks area or winding roads. Be alert to these and take appropriate action. 4-45