If your car is fitted with an advanced emissions control system, which helps your vehicle meet the latest Euro 6 exhaust gas regulations.
AdBlue®, a water/urea based operating fluid, is stored in a tank (like diesel fuel), however, unlike fuel it is not injected into the engine, but directly into a specially modified part of the vehicle's exhaust. This begins a chemical reaction which removes the polluting oxides of nitrogen (NOx), converting them into harmless water and nitrogen in a process known as Selective Catalytic Reduction, or SCR for short. SCR is only applicable to diesel engines and the more economically you drive, typically, the less AdBlue® you will use.
The size of the AdBlue® tank fitted to your car will vary depending on which make and model of car you have, therefore the interval between top-ups will vary. In addition, many factors such as mileage, journey type, driving style and environmental conditions can influence how much AdBlue® is consumed. A passenger car can consume approximately 1.5 litres of AdBlue® every 620 miles.
A series of warnings will be given via the driver information system, accompanied by advice/messages depending on the vehicle you are driving and the warning devices that are in place.
If these warnings are not acted upon, the warning turns red; once this happens the car will not restart once the ignition is turned off. This is not a fault, but a required feature of the system. If this stage is reached the system will need a full top-up before the car can be restarted. Further information is available in the vehicle handbook.