2008 Chevrolet Suburban Owner's Manual - Page 130

{CAUTION: It is dangerous to get out of your vehicle if the shift lever is not fully in PARK (P) with the parking brake firmly set. Your vehicle can roll. Allison Transmission® or Hydra-Matic® 6-Speed Automatic Transmission See "Range Selection Mode" later in this section. PARK (P): This position locks your rear wheels. It is the best position to use when you start the engine because your vehicle cannot move easily. When parked on a hill, especially when the vehicle has a heavy load, you might notice an increase in the effort to shift out of Park. See Torque Lock (Automatic Transmission) under Shifting Into PARK (P) on page 2-44 for more information. Do not leave your vehicle when the engine is running unless you have to. If you have left the engine running, the vehicle can move suddenly. You or others could be injured. To be sure your vehicle will not move, even when you are on fairly level ground, always set your parking brake and move the shift lever to PARK (P). See Shifting Into PARK (P) on page 2-44. If you are pulling a trailer, see Towing a Trailer on page 4-49. 2-32