GMC 2007 Yukon XL Owner's Manual page 147

You can choose among four driving settings:
m
2 (Two-Wheel Drive High): This setting is
used for driving in most street and highway
situations. Your front axle is not engaged in
two-wheel drive. This setting also provides the
best fuel economy.
AUTO (Automatic Four-Wheel Drive): This
setting is ideal for use when road surface traction
conditions are variable. When driving your
vehicle in AUTO, the front axle is engaged, but
the vehicle's power is sent only to the rear wheels.
When the vehicle senses a loss of traction, the
system will automatically engage four-wheel drive.
Driving in this mode results in slightly lower fuel
economy than Two-Wheel Drive High.
m
4 (Four-Wheel Drive High): Use the
four-wheel high position when you need extra
traction, such as on snowy or icy roads or in most
off-road situations. This setting also engages
your front axle to help drive your vehicle. This is
the best setting to use when plowing snow.
n
4 (Four-Wheel Drive Low): This setting also
engages your front axle and delivers extra
torque. You may never need this setting.
It sends maximum power to all four wheels.
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. StabiliTrak will not engage in this mode.
®
See StabiliTrak System on page 348 for
more information.
CAUTION:
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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 151.
NEUTRAL (N): Shift the vehicle's transfer case
to NEUTRAL only when towing your vehicle.
See Recreational Vehicle Towing on page 401 or
Towing Your Vehicle on page 400 for more
information.
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