Volvo VNL 780 Operator's Manual page 346

336 OPERATION
When the idle shutdown feature is enabled, the engine will typically shut down at the set
time under the following conditions:
Vehicle speed is 0.
Engine is running at idle speed.
Coolant temperature is above 45 C (113 F).
Parking brake is applied (Volvo engines only).
These are standard choices when the vehicle is delivered. For more information about other
customer adaptation choices, contact your authorized Volvo Truck dealer.
Uphill Operation
For best performance, allow engine speed to reach the bottom of the rated torque range
before downshifting. Continue to downshift in this manner until a gear is reached that will
maintain the desired speed. Continue to operate at the rated torque if the vehicle will make
it to the top without a downshift. Begin upshifting as the grade of the hill decreases and
the engine begins to accelerate above 1600 rpm. Driving this way will give the best fuel
economy and performance.
Note: Allowing the engine to lug down to the end of maximum torque range is permissible
if the vehicle is cresting the top of a hill. However, extended operation at engine speeds
below the maximum torque range (usually 1000 to 1200 rpm) will raise exhaust temperature
and cylinder pressure. This can lead to reduced engine life.