Chevrolet 2002 Astro Owner's Manual page 218

Tow/Haul Mode
The tow/haul mode is a feature that assists when pulling
a heavy trailer. The purpose of the tow/haul mode is:
D
to reduce the frequency of shifts when pulling a
heavy trailer.
D
to provide the same shift feel when pulling a heavy
trailer as when the vehicle is unloaded.
D
to reduce the need to change throttle position when
pulling a heavy trailer.
This feature is turned on or off by pressing a button on
the column shift lever. When the feature is on, a light on
the instrument panel will illuminate to indicate that the
tow/haul mode has been selected.
See "Tow/Haul Mode Light" in the Index. The tow/haul
mode is automatically turned off each time the vehicle
is started.
The tow/haul mode is most effective when the vehicle
and trailer combined weight is at least 75% of the Gross
Vehicle Weight Rating (GVWR) and the maximum
trailer weight rating for the vehicle. See "Gross Vehicle
Weight Rating" and "Trailer Weight" in the Index.
The tow/haul mode for hauling a heavy trailer is most
useful under the following conditions:
D
When driving through hilly terrain at speeds below
55 mph (88 km/h).
D
When driving in low speed or stop and go traffic
below 55 mph (88 km/h).
D
When driving in parking lots.
Operating in the tow/haul mode when not pulling a
heavy trailer will not cause damage to the vehicle,
but you may experience reduced fuel economy and
undesirable performance from the engine and
transmission. The tow/haul mode should be used
only when pulling a heavy trailer.
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