What's AdBlue and is it Useful?

Jack Dreyer | Monday 21st November 2022 8:00am

Light blue AdBlue cap next to the diesel fuel filler cap on a car manufactured after 2006.

With increasing importance being placed on the reduction of emissions, more and more modifications are being made to vehicles to curb their impact on the environment.

While AdBlue isn’t a new invention (it first came about in 2006), it’s only recently come to the fore for diesel drivers. Namely, the Euro 6 legislation in 2016 stated that nitrogen oxide emissions of diesel cars needed to be reduced to a maximum of 80mh/km.

It’s AdBlue that helps diesel cars meet these standards. But let’s look a little closer at what many perceive to simply be a chore to use.

What does AdBlue do?

Close up of vapour & fumes leaving a car exhaust.

In line with the Euro 6 standards, AdBlue reduces the amount of emissions that come from a diesel car’s exhaust. In fact, some AdBlue suppliers say that it reduces emissions by up to 95%.

While it won’t eliminate all of your car’s emissions, it reduces them significantly. Not only is this vital for the environment, but for our wellbeing, too — as these emissions can contribute to issues with respiratory health.

The colourless, odourless, non-toxic solution is made from urea and demineralised water. When injected into the engine’s exhaust system, it creates a chemical reaction that results in the nitrogen oxide being converted into water vapour and nitrogen. As you might have guessed, water vapour is entirely harmless for the environment!

Is AdBlue useful?

In reducing emissions, AdBlue is absolutely crucial.

On the level of personal use, it’s a legal requirement for vehicles fitted with the technology to use it — a Selective Catalytic Reduction system.

  • Regarding performance, if you don’t refill your AdBlue, two things will happen:
  • The engine’s power will be reduced to limit emissions while driving
  • When you stop, you won’t be able to restart the engine until you’ve put more AdBlue in.

In that sense, AdBlue is vital to staying on the roads!

Does my diesel car need AdBlue?

To check if your car needs AdBlue, simply check if the word ‘blue’ or ‘SCR’ are included in the name of your vehicle. For example, a Citroen BlueHDi and a VW TDI SCR both use it.

Failing that, you can check next to your fuel filler cap, under your bonnet, or in your boot for a blue AdBlue lid.

Person in blue fleece refilling the AdBlue tank of their car.

How to refill AdBlue

If your car uses this emissions-reducing fluid, it’s important to stay on top of replacing it.

Fortunately, AdBlue is available at most garages and motoring shops around the UK in both small and large sizes. We suggest keeping a large bottle at home and a smaller bottle with you on the road in case of emergency.

You can check your handbook to find out exactly how big your AdBlue tank is, but most contain 10 litres or less — and 10 litres should last you a healthy amount of time! Most diesel vehicles consume roughly a litre of AdBlue every 600 miles. So, it follows that 10 litres could last you up to 6,000 miles in theory.

When you do come to refill it, follow these simple steps:

Locate your AdBlue cap (next to the fuel lid, in the boot, or under the bonnet)

Use a funnel to carefully pour the AdBlue in

Screw the cap shut

Wash your hands and the bodywork of the vehicle that it might’ve spilled onto — it can be irritating to skin and damage paintwork

Our AdBlue tips

Here are some general rules of thumb to stick to when using AdBlue:

  1. Fill your AdBlue tank as soon as you notice the warning light to avoid problems restarting.
  2. Refill straight from the container the AdBlue was supplied in to avoid any contamination.
  3. Don’t dilute the product or add any other fluids as this may cause irreversible damage to your car.
  4. Only buy AdBlue from authorised suppliers.
  5. Avoid the diesel tank at all costs — AdBlue has its own tank, and pouring it into the fuel tank can result in needing to replace the whole system.

Issues with your diesel vehicle?

If you’ve got any problems with your car — be it smoke from the exhaust, spongy brakes, or poor performance — don’t hesitate to call your local Kwik Fit garage.

We’re here to help get you back on the roads as soon as possible and with your car performing at its best.

Give us a call or book in for a service here.

Any facts, figures and prices shown in our blog articles are correct at time of publication.

registration plate

Please enter your postcode to see availability information from your local Kwik Fit centre.

Exclusive Online Pricing

We are committed to offering customers our most competitive prices on tyres and more. Read about our exclusive online pricing.

Locate A Centre

Kwik Fit has over 600 centres across the UK including Northern Ireland, many of which are open 7 days a week for your convenience.


We offer a series of FAQs to help you learn more about our services or your vehicle.

Customer Care

0800 75 76 77
You can reach our customer care team 6 days a week from 9:00am to 6:00pm on Monday and Thursday, 8:30am to 6:00pm Tuesday, Wednesday and Friday, 8:30am to 5:00pm Saturday, and 10:00am to 4:00pm on Bank Holidays.