Driving Tips And Techniques Operating Instructions
– 100 – Y53-6008
Medium Duty (R10/06)
• If the engine rpm moves beyond the maximum gov-
erned 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 trans-
mission, 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 exceed the specified load rat-
ing. Overloading can result in loss of vehicle
control and serious personal injury, either by
causing component failures or by affecting vehi-
cle handling. Exceeding load ratings can also
shorten the service life of the vehicle.
•The components of your vehicle are designed
to provide satisfactory service if the vehicle is
not loaded in excess of either the gross vehicle
weight rating (GVWR), or the maximum front and
rear gross axle weight ratings (GAWRs). (Axle
weight ratings are listed on the driver's door
edge.)
NOTE: For your safety and the safety of others, fol-
low routine and periodic maintenance schedules for
all components on your vehicle. See Table 3, “
Main-
tenance Schedule,” Page 123
