operators_manual

Engine Overspeed
CAUTION
To avoid engine damage, do not let the
engine rpm go beyond the maximum
governed rpm—valve damage could
result if overspeed conditions occur.
NOTE
Often these recommendations are
secondary to maintaining an adequate
and safe speed relative to the sur-
rounding traffic and road conditions.
Operate the engine within the optimum
engine rpm range and do not allow the
rpm's to exceed the maximum governed
speed. See your Engine Operation and
Maintenance manual for information
regarding engine rpm. When the engine is
used as a brake to control vehicle speed
(e.g., while driving down a grade), do not
allow the engine rpm to exceed maximum
governed speed. Under normal load and
road conditions operate the engine in the
lower end of the range.
The tachometer is an instrument that aids
in obtaining the best performance of the
engine and manual transmission, serving
as a guide for shifting gears. Refer to the
Engine Operation and Maintenance
manual for optimum engine rpm.
• If the engine rpm moves beyond
the maximum governed speed,
indicating an overspeed condition,
apply the service brake or shift to a
higher gear to bring engine rpm
within the optimum speed range.
• When driving downhill: shift to a
lower gear, use the engine brake (if
so equipped), and use the service
brake, keeping the engine speed
below 2,100 rpm.
When the engine speed reaches its
maximum governed speed, the injection
pump governor cuts off fuel to the engine.
However, the governor has no control over
the engine rpm when it is being driven by
the vehicle's transmission, for example, on
steep downgrades. Apply service brakes or
shift to a higher gear. Fuel economy and
engine performance are also directly
related to driving habits:
• The best results in trip time and
fuel economy are obtained while
driving the vehicle at a steady
speed.
• Shift into higher or lower gears (or
apply the service brake) to keep
engine rpm near the lower end of
the optimum operating range.
• Avoid rapid acceleration and
braking.
WARNING
Do not look at the Instrument Cluster
Display for prolonged periods while the
vehicle is moving. Only glance at the
monitor briefly while driving. Failure to
do so can result in the driver not being
attentive to the vehicle’s road position
or situation, which could lead to an ac-
cident and possible death, personal in-
jury or equipment damage.
The Instrument cluster display provides
information to help the driver optimize
vehicle efficiency. Optimal RPM Indicator
on page 63. A driver will find the section
describing Trip Information and the rpm
detail useful.
Fuel Consumption
The vehicle's fuel consumption is
connected to five important factors:
maintenance, driving habits, general
DRIVING - Driving Tips and Techniques
166 Y53-6047-2HEN (03/18)
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