2008 GMC Acadia Owner's Manual - Page 281

All-Wheel Drive (AWD) System If your vehicle has this feature, engine power is sent to all four wheels when extra traction is needed. This is like four-wheel drive, but there is no separate lever or switch to engage or disengage the front axle. It is fully automatic, and adjusts itself as needed for road conditions. When using a compact spare tire on your AWD equipped vehicle, the AWD system automatically detects the presence of the compact spare and the AWD is disabled. To restore the AWD operation and prevent excessive wear on the clutch in your AWD system, replace the compact spare with a full-size tire as soon as possible. See Compact Spare Tire on page 5-88 for more information. Steering Tips It is important to take curves at a reasonable speed. A lot of the "driver lost control" accidents mentioned on the news happen on curves. Here is why: Experienced driver or beginner, each of us is subject to the same laws of physics when driving on curves. The traction of the tires against the road surface makes it possible for the vehicle to change its path when you turn the front wheels. If there is no traction, inertia will keep the vehicle going in the same direction. If you have ever tried to steer a vehicle on wet ice, you will understand this. The traction you can get in a curve depends on the condition of the tires and the road surface, the angle at which the curve is banked, and your speed. While you are in a curve, speed is the one factor you can control. Suppose you are steering through a sharp curve. Then you suddenly accelerate. Both control systems - steering and acceleration - have to do their work where the tires meet the road. Adding the sudden acceleration can demand too much of those places. You can lose control. See StabiliTrak® System on page 4-6. What should you do if this ever happens? Ease up on the accelerator pedal, steer the vehicle the way you want it to go, and slow down. 4-9 Steering Power Steering If you lose power steering assist because the engine stops or the system is not functioning, you can steer but it will take much more effort. Variable Effort Steering If your vehicle has this steering system, the system continuously adjusts the effort you feel when steering at all vehicle speeds. It provides ease when parking, yet a firm, solid feel at highway speeds.