Volvo VNL Operator's Manual page 245

240 Fuel Economy Driving
Axles
An axle out of alignment will increase
rolling resistance. Regularly check the front
wheel alignment and axles on both the trac-
tor and trailer/semi-trailer. If they are
correct, there will be less rolling resistance,
and therefore, lower fuel consumption.
A good sign of an axle or wheel out of
alignment is uneven tire wear. Check the
tires often.
Engine
Faulty or incorrectly adjusted engine com-
ponents increase fuel consumption. The list
below gives some typical components that
can influence fuel consumption:
•
Blocked (on the outside) charge air
cooler/radiator package
•
Faulty thermostats
•
Blocked fuel filter
•
Blocked air intake filter
•
Faulty injectors
•
Dirty turbo charger
•
Air in fuel system
•
Faulty fuel supply pump
•
Faulty fuel relief valve
•
Faulty fan thermostat/clutch