Audi A5/S5   General maintenance   Checking and topping up fluids  Selective catalytic reduction
On vehicles with selective catalytic reduction, a solution of urea (AdBlue®) is injected into the exhaust system upstream of an NOx catalytic converter in order to reduce nitrogen oxide emissions.
The AdBlue is held in a separate tank on the vehicle. AdBlue consumption is approximately 0.5 - 1.2% of diesel fuel consumption. The AdBlue tank holds about 20 litres.
As soon as a message appears in the instrument cluster display reminding you to refill AdBlue, you must refill the AdBlue tank or have this done by a qualified workshop Link.
Note
  • The instrument cluster display will tell you how far you can drive before the tank runs dry Link. If the AdBlue tank runs dry, the engine cannot be started again after you switch off the ignition.
  • The use of AdBlue for the operation of this vehicle is required by law.
  • AdBlue® is a registered trademark of the German Association of the Automotive Industry e.V. (VDA).

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