To help our environment, some Volkswagen diesel models are now fitted with AdBlue advanced emissions control equipment that cleans exhaust gases to beyond current legislation levels.
It works by injecting a minute amount of a liquid called AdBlue into the exhaust system. The chemicals in AdBlue break down polluting nitrogen oxides into harmless water vapour and nitrogen gas.
The AdBlue liquid is stored in a tank and the more economically you drive, the less you will use.
Typically the AdBlue tank does not need to be replenished until the next scheduled service but this will be dependent upon your driving style, vehicle loading and environmental conditions.
Article source: www.volkswagen.co.uk