climate control VOLKSWAGEN PASSAT 2009 Owners Manual

speed fluctuations caused by taking your foot off the accelerator. Active braking and accelerating is then not necessarily required.
Calm and smooth driving
Consistency is more important than speed. The more smoothly you drive, the less fuel the vehicle consumes.
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 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.
NOTICE
Never let the vehicle coast or roll down a hill in Neutral (N), especially when the engine is not running. The transmission will not be lubricated and will be damaged.

Special considerations
When it is very hot and humid outside, water condensation can drip from the air conditioner evaporator and form a puddle under the vehicle. This is normal and does not indicate a leak.
The climate control system adjusts the passenger compartment temperature as fast as possible considering the outside temperature.
Due to residual moisture in the air conditioner, the windshield may fog up after the engine is started. Switch on the windshield defroster to help evaporate the condensation as quickly as possible.
The air coming out of the vents flows through the passenger compartment and through the vents under the rear window. Do not cover these slots with clothing or other things.
Air vents

Fig. 171 In the instrument panel: Air vents.