AdBlue in diesel vehicles - All you need to know

What is AdBlue?

AdBlue, the new standard for BS6 diesel vehicles, is a trademarked name for an exhaust fluid used in these vehicles. It is not a fuel additive and is colourless.

What is AdBlue made of?

The AdBlue liquid is made up of high-purity urea and de-ionised water. All new-age vehicles powered by a diesel engine come with a separate AdBlue tank. This safe-to-use fluid, along with a Selective Catalytic Reduction (SCR) technology, reduces harmful gases being released into the atmosphere. Cars which don't use SCR use Lean NOx Trap (LNT) tech, like the Hyundais and Kias powered by smaller diesel engines. LNT is also a catalyst which is a low-cost alternative to SCR which also has low emissions of nitrogen oxide (NOx). However, Mahindra still uses SCR in the oil-burner XUV300 hence the need for AdBlue as well.

How does AdBlue work?

Let’s break down this catalytic reduction process and mechanism into two major steps –

• SCR, as mentioned above, is an after-treatment process which includes a chamber in the exhaust pipe. Through sensors and an electronic unit, AdBlue from the tank gets injected into the exhaust system before this SCR catalyst.
• Here, the AdBlue gets heated, decomposes into carbon dioxide and ammonia, and further reacts with the nitrous gases released from the exhaust. However, the reaction causes the harmful nitrous molecules to break down into nitrogen and water.

What does AdBlue do?

As mentioned above, the harmful gases that would have otherwise polluted the environment are now converted into harmless particles and released as steam through the tailpipe.

How does AdBlue help?

NOx emitted from diesel cars is harmful to the environment. Thanks to AdBlue, these emissions are reduced significantly and eventually meet the stringent emission limits set by different standards across the world. It is said that AdBlue fluid treatment helps filter out more than 90 per cent of harmful gas emissions resulting in less pollution.

How do I use AdBlue and what’s its price?

AdBlue Tank’s Capacity and Level Indicator:

The AdBlue catalyst tank capacity varies from 5-20 litres and depends on the diesel vehicle. This capacity is mentioned near the fuel tank lid or in the owner’s manual. According to the distance travelled, the latter helps decide when a top-up or refill is needed. Usually, the authorised workshops take care of this during the vehicle’s service. Meanwhile, there’s a separate indicator on the car’s instrument cluster that displays AdBlue’s quantity with a reserve level.

AdBlue Price in India:

The price of AdBlue may vary from Rs. 85~100 per litre.

Anything else I should know about AdBlue?

The car on the run won't stop midway if the AdBlue level goes low or runs out. However, most cars get an electronic control unit that may reduce power till the AdBlue catalyst is replenished. Once stopped, this unit may not allow you to restart the engine till the AdBlue fluid is topped up. There are places where one can purchase the fluid online and offline, but the best bet is to get it done at the brand dealership.