Volvo VNL 780 Operator's Manual page 309

Driving Habits
The way in which a vehicle is being driven is the one factor which has the greatest influence
on fuel consumption. Correct driving saves fuel and reduces vehicle wear. To achieve
optimal running economy, the driver should always remember to:
•
Start the engine correctly (especially important in winter season).
•
Maintain an even and correct speed.
•
Keep the engine at its optimum speed range.
•
Use the correct uphill and downhill driving technique.
Starting the Engine
Start the engine according to the instructions in the operator's manual of the engine
manufacturer (for a Volvo engine, see "STARTING THE ENGINE" "STARTING THE
ENGINE" page 329). A proper start, especially during the cold season, saves fuel and
reduces engine wear.
Sluggish lube oil in the engine makes cold starting more difficult. Therefore, it is important
to always use engine oil with the correct viscosity. (For the sake of the overall fuel economy,
it is also important to have the right viscosity of transmission and rear axle oils.)
A good sign of an axle or wheel out of alignment is uneven tire wear. Check the tires often.
Avoid High Engine Speeds
High engine speeds mean high fuel consumption. "Jerky" driving also increases fuel
consumption when the vehicle is constantly accelerated and slowed down. Avoid a higher
consumption by steady, even driving.
Refer to each engine manufacturer's operator's manual for information on the engine's
optimum operating range.
Rain, Snow and Road Surface
A wet road surface increases rolling resistance and, thereby, fuel consumption. Slush will
increase consumption even more. In certain cases, the surface structure of the road can also
have a negative effect on fuel consumption.
Hill Driving Technique
Use the inertia of the vehicle to go over the crest of a hill under reduced power. Use gravity
to help with acceleration when going down the hill. Build up speed before reaching the
next uphill.
OPERATION 299