AdBlue is a fuel additive required in modern diesel engines in order to conform to the latest Euro emission regulations. Vaporised AdBlue is injected into the exhaust stream of a diesel engine. When the hot exhaust gases are combined with the AdBlue in the SCR system, it's broken down into pure nitrogen and pure water vapour. These are then expelled through the exhaust pipe.
If your vehicle has a SCR catalyst fitted, you will require AdBlue.
To help you identify the presence of an AdBlue system, the tank has a blue or AdBlue marked cap in close proximity to the fuel cap. AdBlue tanks are typically located either under the bonnet or inside the vehicle. As of September 2014, Euro VI rules require all fleet owners to equip their fleet with a SCR system with AdBlue injection. It will affect standards for diesel driven vehicles.
If a vehicle's AdBlue tank is not topped up and is allowed to run out, most engines will show a dash warning message and either go on a "limp home" mode or not allow the engine to start. If this occurs you must top up with AdBlue as soon as possible. Drivers with Roadside Assistance cover should see if they are eligible to receive an AdBlue top up as part of their plan.
Most commercial vehicles AdBlue tanks will be topped up each time the vehicle is serviced.
One litre of AdBlue is usually sufficient for around 625 miles of driving, however this consumption will be higher depending on the type of driving, mileage and road conditions. Some vehicle manufacturers will specify that AdBlue needs to filled up by themselves at a service, but this isn't the case. Anyone can fill up their AdBlue tank.
AdBlue should be stored in a cool, dry, and ventilated area out of direct sunlight. It is recommended that AdBlue is stored in temperatures up to 25°C.
If stored correctly, AdBlue will last for approximately two years.