AdBlue is a non-toxic, non-flammable, odourless and biodegradable reducing agent that helps to make cars cleaner and more efficient, meaning lower levels of harmful car and van exhaust emissions such as Nitrogen Oxide (NOx).

AdBlue works with a treatment system called ‘Selective Catalyst Reduction’ (SCR), which converts nitric oxide into less harmful nitrogen and water. It is made by mixing a compound made from ammonia and CO2 into deionised water.

The AdBlue fluid is not mixed with the fuel in your vehicle but carried in a separate tank and then pumped into the engine where it is injected into the exhaust gases. Working together with the catalyst, Adblue converts 80% of the NOx coming from the vehicles combustions chambers into harmless nitrogen and water.

Many HGVs, buses and other large diesel vehicles have been using AdBlue for several years. From September 2015 all new vehicles sold in the EU must meet the Euro 6 (EU 6) emissions standard; therefore new diesel cars feature an AdBlue injection system.

Consumption will depend on driving style, journey type, road conditions and the load placed on your engine, so topping up your AdBlue tank may be required between services.

You can refill the tank yourself when alerted by your Driver Information System, or take your car to an Audi Authorised Repairer. Your driver information system will display a warning when the fluid is running low at three intervals. The warning will start at 1500 miles and count down.

Audi supplies AdBlue for £1.50 per litre, including VAT and labour. Contact your local Audi Centre or watch the video to find out more about AdBlue.

AdBlue is not exclusive to Audi and can be purchased from a number of outlets. We recommend customers only use reputable AdBlue products in their cars, i.e. those that meet ISO standard 22241-1.