outside temperature. It may be helpful to ventilate the vehicle before 
driving and then to drive a short distance with the windows open. Af-
ter that, switch on the air conditioner with the windows closed. Keep 
the windows closed when driving at high speeds. Open windows in-
crease fuel consumption. 
  Switch off seat heating once it has served its purpose. 
  Switch off the rear window defroster as soon as the windows are 
free of fog and ice. 
Additional factors that increase fuel consumption (examples): 
  Malfunctioning engine control. 
  Driving in the mountains. 
  Towing a trailer. 
  NOTICE 
Never let the vehicle coast or roll down a hill in Neutral (N), es-
pecially when the engine is not running. The transmission will 
not be lubricated and will be damaged. 
Fuel-efficient driving 
 
Fig. 147 Fuel consumption in mpg at 2 different outside air tempera-
tures.