Many diesel vehicles built after September 2015, but not all, require AdBlue. But what is it? Our blog explains.

What is AdBlue?

AdBlue is a fuel additive, also known as diesel exhaust fluid or DEF. Vehicles that require Adblue will have a filler inlet separate to the fuel filler inlet, so it is not added to the fuel. AdBlue is a fluid, and vehicles automatically spray it into the car’s exhaust system to reduce the nitrous oxide emissions of diesel engines.

AdBlue reduces the emissions in diesel vehicles so they can comply with stricter Euro 6 emissions standards that came into effect in 2016.

AdBlue levels should be checked and topped up when servicing the vehicle, although most vehicles have a gauge to tell you when you are running low.

Why do we need AdBlue, and how does it work?

The most recent set of emissions regulations (Euro 6) presented a huge challenge for diesel engines, as one of the main goals of Euro 6 was to minimise nitrogen-oxide emissions. The emission reducing technology is known as selective catalytic reduction (SCR), which involves injecting liquid into the exhaust system, causing a chemical reaction to neutralise harmful emissions.

What is AdBlue made of?

AdBlue is made up of a solution of demineralised water (making it cleaner than tap water), and urea – a substance found in urine.

When buying AdBlue for your vehicle, make sure it meets the correct specification by looking for the ISO 22241 number on the label (it may also appear as ISO-22241-1, ISO-22241-2, ISO-22241-3), otherwise it could damage the vehicles SCR catalyst, which is expensive to repair.

Where can I buy AdBlue?

AdBlue can be bought from most fuel stations and auto factors, and can be ordered online.

Can I refill AdBlue myself?

Yes you can. Most of the time the AdBlue filler will be found near the main fuel filler, and should be labelled accordingly. You can refill straight from the bottle, or even by using a pump found at filling stations.

What should I do if I have an AdBlue warning light?

If you see an AdBlue warning light, that means you vehicle is due a top up. But don’t worry, most vehicles will give you plenty of notice and won’t wait until levels are too low before informing you – you’ll usually be alerted with a dashboard warning at around 1,500 miles from running out completely.

What happens if I run out of AdBlue?

If you run out of AdBlue, then the vehicles performance could be affected. This is because without AdBlue to reduce emissions, the vehicle will try and reduce emissions by reducing performance and going into ‘limp mode’, reducing the vehicles power. Once the vehicle has stopped, it cannot be started again until the AdBlue tank has been refilled.

Any Questions?

If you have any questions about AdBlue for your lease vehicle, don’t hesitate to get in touch one of our experts.