•The cooling function of the air conditioning system: if the air conditioning system is set to a very
high or low temperature it will require a lot of energy, which is generated by the engine.
Therefore the temperature setting in the vehicle should not vary too much from the outside
temperature. It may be a good idea to air the vehicle before setting off and then to travel a short
distance with the windows open. The air conditioning system should then be switched on once
the windows have been closed.
•Keep the windows closed when driving at high speeds. Having the windows open increases fuel
consumption.
•Switch the seat heating off as soon as it has served its purpose.
•Switch the rear window heating off as soon as the window has defogged and is clear of ice.
Other factors that increase fuel consumption (examples):
•Fault in engine management.
•Driving in hilly regions.
Driving in a fuel-efficient manner
Fig. 102 Fuel consumption in litres per 100 km at two different outside temperatures
First read and observe the introductoryinformation and safety warnings⇒
Introduction
By adopting an economical driving style and anticipating the traffic situation ahead, you can easily
reduce fuel consumption by 10-15 %.
Cars use most fuel when accelerating. If you think ahead when driving, you will need to brake less
and thus accelerate less. Wherever possible, let the car roll slowly to a stop, for instance when you
can see that the next traffic lights are red.
Avoid short journeys
Directly after a cold start, the engine has a very high fuel consumption. The engine reaches its
working temperature after a few kilometres, when fuel consumption will return to a normal level.
The engine and catalytic converter need to reach their proper working temperature in order to
minimise fuel consumption and emissions. The outside temperature is a key factor.
The different rates of fuel consumption for the same distance at both +20°C (+68°F) and at -
10°C (+14°F) are shown in ⇒ Fig. 102.
Therefore, avoid making too many short journeys and car share whenever possible.
Under the same conditions, the vehicle will use more fuel in winter than in summer.
Not only is it illegal in some countries to warm up the cold engine by running it while the vehicle is
stationary, it is also technically unnecessary and a waste of fuel.
Adjust the tyre pressure
The correct tyre pressure reduces rolling resistance and therefore also fuel consumption.
Ensure that any new tyres purchased have optimum rolling resistance.
Using low viscosity engine oils
Fully synthetic low viscosity engine oils reduce fuel consumption. Low viscosity engine oils
decrease frictional resistance in the engine and spread better and more quickly, especially for cold
starts. They are especially effective in vehicles that make a lot of short journeys.
Always ensure that the engine oil level is correct and that you keep to the service intervals (oil
change intervals).
When buying engine oil, always ensure that it complies with engine oil norms and has been
approved by Volkswagen.
