GMC 2009 Sierra 1500 Crew Cab Owner's Manual page 128

R (Reverse): Use this gear to back up.
Notice: Shifting to R (Reverse) while the vehicle is
moving forward could damage the transmission.
The repairs would not be covered by the vehicle
warranty. Shift to R (Reverse) only after the vehicle
is stopped.
To rock the vehicle back and forth to get out of snow, ice,
or sand without damaging the transmission, see If Your
Vehicle is Stuck in Sand, Mud, Ice, or Snow on
page 4-32.
N (Neutral): In this position, the engine does not
connect with the wheels. To restart when you are
already moving, use N (Neutral) only. Also, use
N (Neutral) when the vehicle is being towed.
CAUTION:
{
Shifting into a drive gear while the engine is
running at high speed is dangerous. Unless your
foot is firmly on the brake pedal, the vehicle could
move very rapidly. You could lose control and hit
people or objects. Do not shift into a drive gear
while the engine is running at high speed.
2-30
Notice: Shifting out of P (Park) or N (Neutral) with
the engine running at high speed may damage
the transmission. The repairs would not be covered
by the vehicle warranty. Be sure the engine is
not running at high speed when shifting the vehicle.
D (Drive): This position is for normal driving. It provides
the best fuel economy. If you need more power for
passing, and you are:
•
Going less than about 35 mph (55 km/h), push the
accelerator pedal about halfway down.
•
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
By doing this, the vehicle shifts down to the next gear
and has more power.
D (Drive) can be used when towing a trailer, carrying a
heavy load, driving on steep hills, or for off-road
driving. You might want to shift the transmission to a
lower gear selection if the transmission shifts too often.
Downshifting the transmission in slippery road conditions
could result in skidding. See Skidding under Loss of
Control on page 4-11.