FORD 2006 F-550 v.1 - Manual (Page 177)

N (Neutral)
With the gearshift lever in N (Neutral), the vehicle can be started and is
free to roll. Hold the brake pedal down while in this position.
D (Overdrive) with Tow/Haul OFF
D (Overdrive) with Tow/Haul OFF is the normal driving position for the
best fuel economy. The overdrive function allows automatic upshifts and
downshifts through gears one through five.
D (Overdrive) with Tow/Haul ON
The Tow/Haul feature improves transmission operation when towing a
trailer or a heavy load. All transmission gear ranges are available when
using Tow/Haul.
To activate Tow/Haul, press the
button on the end of the gearshift
lever.
The TOW HAUL indicator light will
illuminate in the instrument cluster.
Tow/Haul delays upshifts to reduce frequency of transmission shifting.
Tow/Haul also provides engine braking in all forward gears when the
transmission is in the D (Overdrive) position; this engine braking will
slow the vehicle and assist the driver in controlling the vehicle when
descending a grade. Depending on driving conditions and load
conditions, the transmission may downshift, slow the vehicle and control
the vehicle speed when descending a hill, without the accelerator pedal
being pressed. The amount of downshift braking provided will vary based
upon the amount the brake pedal is depressed.
To deactivate the Tow/Haul feature and return to normal driving mode,
press the button on the end of the gearshift lever. The TOW HAUL light
will no longer be illuminated.
When you shut-off and restart the engine, the transmission will
automatically return to normal D (Overdrive) mode (Tow/Haul OFF).
Do not use the Tow/Haul feature when driving in icy or slippery
conditions as the increased engine braking can cause the rear
wheels to slide and the vehicle to swing around with the possible loss
of vehicle control.
2006 F-250/350/450/550 (f23)
Owners Guide (post-2002-fmt)
USA (fus)
Driving
177