Chevrolet Silverado 2007 Owner's Manual page 156

You might choose Four-Wheel-Drive Low if you
are driving off-road in deep sand, deep mud, deep
snow, and while climbing or descending steep hills.
When operating in Four-Wheel Low, the gear ratio
provides additional torque when compared to
Four-Wheel-Drive High. The transmission gear
shift feel is exaggerated.
156
A parking brake symbol
is located next to the
N (NEUTRAL) symbol
as a reminder to set the
parking brake before
shifting the transfer
case in Neutral.
CAUTION:
{
Shifting the transfer case to NEUTRAL
can cause your vehicle to roll even if the
transmission is in PARK (P). You or
someone else could be seriously injured.
Be sure to set the parking brake before
placing the transfer case in NEUTRAL.
See Parking Brake on page 169.
N (NEUTRAL): Shift to this setting only when
your vehicle needs to be towed. See Recreational
Vehicle Towing on page 443 or Towing Your
Vehicle on page 443
m
2 (Two-Wheel-Drive High): This setting is
used for driving in most street and highway
situations. The front axle is not engaged in
two-wheel drive. This setting also provides
the best fuel economy.