Kenworth T410, Driver'S Handbook Manual

Page: 219 / 418

CAT: 8612 November 2019 Page 193
OPERATING INSTRUCTIONS
ECONOMICAL DRIVING
The following section includes recommendations for best engine
performance and economy.
Engine Overspeed - RPM:
• Operate the engine within the optimum engine rpm range and do
not allow the rpm 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.
To avoid engine damage, do not let the engine rpm go beyond the
maximum governed rpm. Valve damage could result if overspeed
conditions occur.
Often these recommendations are secondary to maintaining an adequate
and safe speed relative to the surrounding traffic and road conditions.
Use of Tachourmeter
The tachourmeter is an instrument that helps you obtain 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 greater than 1200rpm and below 2000rpm .
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.