What is AdBlue and Why is it Important?

01st Feb 2022

By Daniel Hitchman


If you own a diesel car built after September 2015, or are currently looking at used cars that fall into this category, you may or may not be aware of their need for a fluid called AdBlue.

Like anything automotive, it may seem daunting or complicated, but in reality it's just a fluid added to a diesel car to make it more environmentally friendly, whilst making it comply with the ever-changing standards regarding emissions.

Therefore, below we have compiled a list of all the common questions surrounding AdBlue, along with all the necessary answers.

What is AdBlue?

AdBlue is a biodegradable, completely harmless solution designed to help diesel vehicles meet the latest Euro exhaust emissions regulations.

AdBlue is made from 32.5 percent urea and 67.5 percent deionized water. And no, it's not actual urine, it's made from synthetic materials.

How does AdBlue work?

Typically, modern diesels utilise a treatment system called Selective Catalytic Reduction (SCR to you and us). Essentially, the SCR blends the AdBlue with the engine's exhaust gasses, which creates a chemical reaction, to convert nitrogen oxides (NOx) into nitrogen, water and carbon dioxide (CO2). As a result, the gasses emitted are less harmful to the environment and our health.


Does my car have an SCR system?

The SCR system is typically found on diesel powered vehicles that have been designed to meet Euro 6 regulations. Euro 6 was introduced in 2014, so any diesel vehicle built after that should, in theory, utilise AdBlue. Typically, the more recent the diesel powered car, the more likely it is to use an SCR system.

If you're in any doubt, then consult with your vehicle's handbook.

What happens if I don't fill up my car's AdBlue tank?

SCR equipped cars typically reduce engine performance, with some not starting at all if AdBlue levels are completely depleted. Don't worry about it though, because a low-level warning light will appear on your vehicle's dashboard long before you run out.

AdBlue Level

Where do I find AdBlue?

A wide variety of fueling stations will have AdBlue in abundance, whether it's as a standalone pump, or as large containers you can take home. Alternatively, you can find AdBlue being sold at local car dealerships, supermarkets, and online.

How much is AdBlue?

Prices vary greatly across locations and sellers, but a few searches around local and national sellers suggest that £1.00 per litre is around the going rate. Evans Halshaw Peugeot, for example, offer a flat rate of 10 litres for £9.99, which is very good.

Hyundai KONA  Engine

On top of fuel, that's going to sting me financially, isn't it?

Not as much as you'd think. Consumption is completely dependent on the vehicle, your driving style, and the journey. However, it could be anywhere from 3,000 to 12,000 miles between refills. It's not uncommon to have to refill your tank at least once between dealer services.

How do I refill the tank?

Similar to refilling your diesel tank, there will be an AdBlue filler cap somewhere on your car. Where the filler nozzle is completely varies from car to car, so we would recommend checking your vehicle's handbook.

Hyundai KONA

Contact Evans Halshaw

If you have any doubts regarding AdBlue and its use in your car, please don't hesitate to contact your nearest Evans Halshaw retailer, who will have knowledgeable team members on standby ready to assist you with any queries.