AdBlue

What is AdBlue?

AdBlue is an important addition added to your diesel van to reduce harmful emissions. All new diesel vans will use AdBlue in order to conform to the latest European emissions standards – currently Euro 6.

AdBlue is a mixture of water and urea, which you top up periodically, as you do with fuel. As you drive, AdBlue flows from the tank into the exhaust pipe via a dedicated catalyst. The effect is a chemical reaction that converts most of the NOx molecules into nitrogen and water. This is then released into the atmosphere as steam

As part of the overall drive to reduce emissions, and to comply with Euro 6 standards, more and more diesel cars and vans now include SCR (Selective Catalytic Reduction) technology. Used in the right way, SCR can help to reduce Nitrogen Oxide (NOx) emissions by as much as 90%, with fuel efficiency also increasing by between 3% and 5%.

How do I use Ad Blue?
For the emissions reducing technology to work, vehicles need to be fitted with a special tank for storing a liquid-reductant agent known as AdBlue®. If your vehicle is designed to use AdBlue®, there are a few things you’ll need to know to keep it running smoothly.

How do I fill up the AdBlue tank?
AdBlue® is readily available from fuel stations and motorway services. New vehicles tend to have a filling point next to the fuel cap, however it does vary depending on the manufacturer and model. So, it’s best to refer to the owner’s manual before you start.

How will I know when to fill up on AdBlue?
It’s important to top up your AdBlue as soon as you see any relevant warning lights on your dashboard. There are three possible warnings:

• First Warning – advises you that the AdBlue® tank is getting low
• Second Warning – will give you a mileage range and sometimes is accompanied by an acoustic warning
• Final Warning – at this point the vehicle will either go into limp home mode (run at reduced power) or will not restart once the ignition has been switched off.

Who pays for AdBlue®?
Because it’s a solution you top up periodically, the costs are not covered by any maintenance contracts you may have taken out and you’ll pay for AdBlue as you would fuel. The only exception to this is if the service schedule states that the fluid needs to be changed (rather than topped up).

Last updated March 2026