2011 Buick Enclave Owner's Manual - Page 246

9-8 Driving and Operating Hill and Mountain Roads Driving on steep hills or through mountains is different than driving on flat or rolling terrain. Tips for driving in these conditions include: . { WARNING If you do not shift down, the brakes could get so hot that they would not work well. You would then have poor braking or even none going down a hill. You could crash. Shift down to let the engine assist the brakes on a steep downhill slope. . Stay in your own lane. Do not swing wide or cut across the center of the road. Drive at speeds that let you stay in your own lane. Top of hills: Be alert - something could be in your lane (stalled car, accident). Pay attention to special road signs (falling rocks area, winding roads, long grades, passing or no-passing zones) and take appropriate action. . Keep the vehicle serviced and in good shape. Check all fluid levels and brakes, tires, cooling system, and transmission. Shift to a lower gear when going down steep or long hills. . . . { WARNING Coasting downhill in N (Neutral) or with the ignition off is dangerous. The brakes will have to do all the work of slowing down and they could get so hot that they would not work well. You would then have poor braking or even none going down a hill. You could crash. Always have the engine running and the vehicle in gear when going downhill.