When driving on the highway or freeway, a constant, moderate speed is more efficient and
economical than constantly accelerating and braking. Usually you can reach your destination just as
quickly by driving at a moderate, but steady speed.
The cruise control system can assist in maintaining a uniform driving style.
Moderate use of extra electrical loads
Comfort inside the vehicle is nice and important, but it is important to use them in an environmentally
conscious manner.
Some devices can increase fuel consumption when activated (examples):
x Climate control system (air conditioner): If the climate control system has to produce starkly
contrasting temperatures, it requires a large amount of energy, which is generated by the engine. The
temperature in the vehicle should therefore not be extremely different from that of the outside
temperature. It may be helpful to ventilate the vehicle before driving and then to drive a short distance
with the windows open. After that, switch on the air conditioner with the windows closed. Keep the
windows closed when driving at high speeds. Open windows increase fuel consumption.
x Switch off seat heating once it has served its purpose.
x Switch off the windshield and rear window defroster as soon as the windows are free of fog and
ice.
Additional factors that increase fuel consumption (examples):
x Malfunctioning engine control.
x Driving in the mountains.
x Towing a trailer.
Fuel-efficient driving
Fig. 249 Fuel consumption at 2 different outside air temperatures.