2008 GMC Envoy Owner's Manual - Page 259

Driving Downhill When off-roading takes you downhill, you will want to consider a number of things: • How steep is the downhill? Will I be able to maintain vehicle control? • What is the surface like? Smooth? Rough? Slippery? Hard-packed dirt? Gravel? • Are there hidden surface obstacles? Ruts? Logs? Boulders? • What is at the bottom of the hill? Is there a hidden creek bank or even a river bottom with large rocks? If you decide you can go down a hill safely, then try to keep your vehicle headed straight down, and use a low gear. This way, engine drag can help the brakes and they will not have to do all the work. Descend slowly, keeping your vehicle under control at all times. There some things not to do when driving down a hill. These are important because, if you ignore them, you could lose control and have a serious accident: • When driving downhill, avoid turns that take you across the incline of the hill. A hill that is not too steep to drive down may be too steep to drive across. You could roll over if you do not drive straight down. • Never go downhill with the transmission in NEUTRAL (N). This is called "free-wheeling." The brakes will have to do all the work and could overheat and fade. Your vehicle is much more likely to stall when going uphill. But if it happens when going downhill: 1. Stop your vehicle by applying the regular brakes. Apply the parking brake. 2. Shift to PARK (P) and, while still braking, restart the engine. 3. Shift back to a low gear, release the parking brake, and drive straight down. 4. If the engine will not start, get out and get help. {CAUTION: Heavy braking when going down a hill can cause your brakes to overheat and fade. This could cause loss of control and a serious accident. Apply the brakes lightly when descending a hill and use a low gear to keep vehicle speed under control. 4-21