2012 GMC Sierra Owner's Manual - Page 282

9-6 . Driving and Operating Try to avoid sudden steering, acceleration, or braking, including reducing vehicle speed by shifting to a lower gear. Any sudden changes could cause the tires to slide. { WARNING When driving off-road, bouncing and quick changes in direction can easily throw you out of position. This could cause you to lose control and crash. You and your passengers should always wear safety belts. To gain more ground clearance if needed, it may be necessary to remove the front fascia lower air dam. Notice: Operating the vehicle for extended periods without the front fascia lower air dam installed can cause improper air flow to the engine. Re‐attach the front fascia air dam after off-road driving. Remember: Antilock brakes help avoid only the braking skid. Off-Road Driving Four-wheel-drive vehicles can be used for off-road driving. Vehicles without four-wheel drive and vehicles not equipped with All Terrain (AT) or On-Off Road (OOR) tires must not be driven off-road except on a level, solid surface. To contact the tire manufacturer for more information about the original equipment tires, see the Limited Warranty and Owner Assistance Information manual. Controlling the vehicle is the key to successful off-road driving. One of the best ways to control the vehicle is to control the speed. . Before Driving Off-Road Have all necessary maintenance and service work completed. Fuel the vehicle, fill fluid levels, and check inflation pressure in all tires, including the spare, if equipped. Read all the information about four-wheel-drive vehicles in this manual. Make sure all underbody shields, if equipped, are properly attached. Know the local laws that apply to off-road driving. Loading the Vehicle for Off-Road Driving . { WARNING . . . Unsecured cargo on the load floor can be tossed about when driving over rough terrain. You or your passengers can be struck by flying objects. Secure the cargo properly. (Continued) .