Volvo VN, Operator'S Manual

Page: 272 / 456

OPERATION 263
FUEL ECONOMY DRIVING
General
The absolute fuel consumption (counted in liters per 100 kilometers or miles per US
gallon) is determined by a large number of circumstances which can be related to one
of the following main areas:
•
Build specification and equipment
•
Service and maintenance
•
External environment
•
Driving habits
Due to these factors, fuel consumption can vary considerably within what is called
"normal fuel consumption." Fuel consumption can vary from over 24 L/100 km (10
mpg) when driving empty on a nice and dry summer road to 67 L/100 km (3.5 mpg)
while driving with maximum permitted GVW, with vehicle and trailer, on a hilly
and slushy winter road.
Build Specification and Equipment
Whenever a vehicle is used for transportation, its build specification, equipment and
gross vehicle weight have a decisive effect on both fuel consumption and performance.
The factors which have the greatest influence on fuel consumption are primarily:
driveline combination, height of trailer or superstructure, use of air fairings, tire type,
number of wheels, gross vehicle weight, and accessories.
Driveline Combination
Engine, transmission and final drive must be selected in such a way that the engine
can operate within the economic speed range at normal driving speed. This range is
defined as where the engine makes the best use of the energy content of the diesel fuel.
A poorly selected rear axle ratio, which results in the engine speed being constantly
above the optimum speed, will increase fuel consumption.