TM 9-2320-303-10
2-14.
DRIVING TIPS (Con't).
c.
Drive efficiently and economically.
(1)
Driving at Highway Speed. Recommended normal highway cruising
range is 1800 - 1900 rpm. If operating on hilly terrain, in high winds, or in other conditions that
make it impractical to operate without reserve power, operate vehicle in lower gear.
(2)
Driving in City. When slowing for posted speed zones, remain in Drive
(D) position and reduce engine rpm.
(3)
Driving Uphill (Under Load). Proper use of gears shortens time on hills
and minimize amount of shifting. As vehicle starts uphill, press accelerator pedal as required
to maintain speed.
WARNING
DO NOT use engine brake if road surfaces are slippery. Use of engine
brake on wet, icy, or snow-covered roads could result in loss of vehicle
control. Failure to follow this warning could result in death or injury to
personnel or damage to equipment.
(4)
Use Engine as a Braking Force. The vehicle is equipped with an engine
braking system that enables the engine to act as a brake. The engine brake should be used
for descending grades and is most effective between 1750 - 2100 rpm.
(a)
If maximum engine braking is required, turn both engine brake
selection switches up to engage six cylinders.
(b)
If less than maximum engine braking is required, turn left engine
brake selection switch up and right engine brake selection switch down to engage two
cylinders, or left engine brake selection switch down and right engine brake selection switch
up to engage four cylinders.
(5)
Downhill Braking.
(a)
Select a gear that allows engine, with engine brake applied, to
control vehicle speed with engine rpm at or below 2100 rpm without applying service brakes.
As downgrade is approached, progressively select a gear that, when combined with engine
brake, will allow you to maintain engine speed of 1750 - 2100 rpm.
(b)
As engine speed exceeds 2100 rpm, use one positive application of
service brakes to slow engine speed to 1650 rpm, release engine brake, downshift one gear,
and apply engine brake. Repeat this procedure until engine speed can be maintained at
1750 - 2100 rpm.
2-68
