What is AdBlue?
Diesel engines emit more harmful substances into the air compared to the petrol-based ones. European emission standards regulate the emission levels of new vehicles sold in the EU.
You have surely heard of Euro 1 and 2-6 standards, which set the maximum emission values for nitrogen oxides, hydrocarbons, carbon monoxide and particulates.
To protect our environment, emission standards regarding harmful substances have become stricter. In the case of some vehicles, the application of purely technical solutions was not sufficient to reach these set standards, so this situation required "external assistance".
This is where AdBlue, an additive, comes into play that greatly reduces nitrogen oxide emissions for diesel engines. AdBlue is a solution with a urea content of roughly 32% (urea is a colourless crystalline compound, a product of amino acid degradation, and is also found in the human body). If your car has no diesel fuel smell, then you can be pretty sure that it comes with AdBlue.
What does AdBlue do?
The AdBlue fluid is injected into the exhaust gas before it enters the catalytic converter. The system requires high temperatures (minimum 250 Cₒ) to be able to react chemically, which is more difficult to achieve under lighter load such as urban use of the vehicle. For this reason, the exhaust temperature is raised to warm the catalytic converter faster to the desired temperature in these vehicles. Due to the heat, ammonia is released, which reacts with the nitrogen oxides of the exhaust gas to convert those into nitrogen and water.
- At what temperature does it freeze? -11 degrees Celsius.
- What changes during the drive? You won't notice a difference. The vehicle's equipment will let you know in a timely manner when it is necessary to refill AdBlue.
- What happens if I run out of it? The vehicle will remain operable, though some brands will reduce the power to "force" the driver to refill.
- How much of it is it needed for a tank of diesel? Since a separate tank is available and the "mixing" of the fluids is controlled by the vehicle's control unit, you just have to ensure that there is always some AdBlue fluid in the tank. On average, it needs to be refilled every 8 to 10 thousand kilometres.
- Is AdBlue a type of fuel? Yes.
- It's hard to fill the tank, can my clothes get dirty? AdBlue is sold at petrol stations. Where it is available in a can, I would say it is comparable to filling the windscreen wiper fluid tank. If a separate filling gun is available, it works like the usual refuelling process.
- Do I need to go to a service centre to have my car refilled with AdBlue? No! You can easily perform the process yourself. AdBlue is a non-flammable, non-toxic material and it is non-hazardous when it comes to storage and transport. All you have to do is ensure the AdBlue fluid stays uncontaminated in case of storage. If it's watered down, or contaminated with oil, that can cause huge issues in the catalytic converter and for the control unit.
author: Endre Deáki - ALD Head of Technical, Body Repair and Invoicing