February 6, 2023 - Reidy Remaps

What is AdBlue?

All modern diesel cars adhere to the latest emission standards and use a liquid called AdBlue. The liquid helps in removing toxic substances from the car’s exhaust gases. But what exactly is it?

AdBlue is a brand name technically known as diesel exhaust fluid, a mixture of urea and distilled water. AdBlue is a colourless and nontoxic fluid that feels sticky but washes off easily. However, it corrodes metallic surfaces.

What is Adblue Made From?

It is made from 2/3 deionised water and 1/3 high-purity urea. The high-purity urea contains ammonia which helps in reducing the NOx gases before they emit from your car.

How Does AdBlue Work?

AdBlue is automatically pumped into your car’s exhaust system, mixing with the exhaust gases, including the NOx, as part of the Selective Catalytic Reduction, or SCR, system. With the help of AdBlue, the NOx is converted into inert oxygen and nitrogen that are released into the atmosphere together with the exhaust pipe.

Although AdBlue doesn’t altogether remove your car’s NOx emissions, it significantly lowers them.

Understanding Selective Catalytic Reduction

Selective Catalytic Reduction, or SCR, is a high-tech emission control system that helps reduce NOx emission. When your car engine runs, a small amount of AdBlue particles is added to the exhaust. Then the liquid’s ammonia combines with the hazardous NOx gases to produce nitrogen and water.

Why Does Your Diesel Car Need AdBlue?

AdBlue is required to clean the exhaust gases of diesel cars. Since 2015, according to Euro 6 emissions standards, only a limited amount of NOx can be emitted legally from your car as these gases are toxic waste products of the combustion process.

These emissions have been connected to respiratory illnesses that can have a negative impact on people’s health. Even though a single automobile only generates relatively small levels of NOx, when thousands of diesel vehicles combine their emissions, the air quality in your town or city can get noticeably worse. And that could be harmful to your family’s and your own health.

How Much AdBlue will be Used by Your Car?

AdBlue consumption depends on the vehicle’s model you drive. However, the faster you drive, the more AdBlue your car will consume. For instance, for every 620 miles, a Volkswagen Passat uses approximately 1.5 litres.

Can Issues Arise from Lack of AdBlue?

A lack of AdBlue can create significant issues, one of them being that the car won’t start. The reason is that the system has a great impact on the emission performance of the engine. The vehicles are designed to run with an AdBlue; therefore, they cannot be driven like old-fashioned cars. If no AdBlue is added to your car, it will most likely go into limp mode.

A limp mode can be described as when ECU (Engine Control Unit) reduces the engine power and locks out the gears. Meaning you will literally crawl along at low speeds.

Moreover, if you have stored your AdBlue in your garage, ensure you put it into an expandable container because, in cool weather, it can freeze and expand at least by 7%. In such a case, it can burst and cause a mess and an unpleasant smell.

Additionally, running out of AdBlue is not the only reason your car will go into limp mode. If there is an issue with your gearbox or engine, in these cases, your car will also activate the limp mode.

Can You Refill AdBlue Yourself?

You don’t have to refill AdBlue tank yourself as it is recommended to always refill by technicians. However, if you choose to refill, ensure your skin does not come in contact with the liquid and avoid any spillage, as it can damage your car’s paint. In case of a spill, whether on your hands or clothes, you can just wash the area thoroughly.

To refill AdBlue, you can see a blue cap for the AdBlue right behind the fuel filler cap. You can easily find a container of AdBlue at filling stations for around £15 to £20. Other than containers, some fuel stations have AdBlue pumps, so you may quickly fill your car.

You have to ensure you don’t accidentally pour AdBlue into the diesel tank; otherwise, your tank will need cleaning and draining. Fortunately, now that cars are designed with the latest technology, you cannot accidentally put AdBlue in the diesel tank because the pump nozzle is comparatively big.

Which of the Cars Use AdBlue?

Many diesel cars that are manufactured according to Euro 6 emission use AdBlue. However, not all cars use AdBlue, as other systems can be used instead to reduce NOx emissions.

Here are some tips to check whether your car requires AdBlue or not.

You can check by locating the “blue” or letters “SCR” are part of the car’s name.
For instance, Citroen and Peugeot are bagged BlueHDi.
Fords are bagged Eco Blue.
Volkswagens are badged IDI SCR.
Or you can check the fuel filler flap to see whether a blue-capped AdBlue filler is mentioned.
If you are still unsure, you can ask your dealer or the manufacturer.

How to Check How Much AdBlue is Left in Your Car?

The cars that use AdBlue have a gauge on the dashboard, showing how much AdBlue is left in your car. A warning light will turn on the dashboard; ask your dealer if you still cannot find it.