What is AdBlue

AdBlue is a type of diesel exhaust fluid (DEF) that reduces the amount of harmful nitrogen oxides (NOx) emitted by a diesel engine. The colourless, non-toxic liquid is stored in separate AdBlue tanks and injected directly into the exhaust streams, making it neither an additive nor a fuel.

What is AdBlue?

• AdBlue is a non-toxic, colorless, odorless, and non-flammable fluid that's injected into the exhaust system of diesel vehicles to reduce harmful emissions.
• AdBlue is a mixture used in all heavy-duty diesel engines produced – primarily Euro 6-compliant models. AdBlue is not a fuel additive as itʼs added to the exhaust gas after combustion has taken place.
• By regulating vehicular NOx emissions and advocating for AdBlue usage, governments worldwide are promoting cleaner air and safeguarding against the health risks associated with diesel pollution.

What Is AdBlue Made Of?

AdBlue is a colourless mixture of highly-purified adBlue grade urea (32.5%) and highly-purified pharmaceutical grade deionised water (67.5%).The urea in AdBlue contains ammonia, which is the active ingredient that reacts with and neutralizes NOx before it enters the atmosphere.

• Deionized Water (67.5%): The water used in DEF is deionized to remove any minerals, salts, or impurities that could potentially damage the Selective Catalytic Reduction (SCR) system or reduce its effectiveness.
• Urea (32.5%): The urea used in AdBlue is highly purified and derived synthetically. It is a nitrogen-based compound (chemical formula CO(NH₂)₂) that, when heated in the SCR system, breaks down into ammonia (NH₃)

How does AdBlue work?

AdBlue is a high purity, 32.5% urea solution directly injected into the exhaust gas where it serves as reducing agent. The released ammonia subsequently reacts with the nitric oxides on the catalyst to form elementary nitrogen and water; both are natural constituents of the air we breathe. Hence, the amount of nitric oxides in the emission can be reduced.

What happens if I run out of Adblue?

If you run out of AdBlue while you’re driving, then the engine’s power and performance will be reduced to limit its emissions. Once you’ve stopped, you won’t be able to restart the engine if the AdBlue tank’s empty. The car will give you plenty of warning that the AdBlue tank is running low. You'll usually see a text warning on the dashboard when there's around 1500 miles' worth of AdBlue left.

How much AdBlue does my car use and how long does it last?

A typical diesel engine needs enough AdBlue to match 4-6% of the amount of diesel it uses. In other words, the engine needs 4-6 litres of AdBlue for every 100 litres of fuel it consumes. AdBlue consumption is quite consistent and predictable, making it easy for you to forecast how much you need regularly.

What is the Adblue warning light?

The Adblue warning light is an indicator on your car’s dashboard. It signals when Adblue levels are low and is usually accompanied by a milage countdown. When the light is on your car’s Adblue tank needs to be refilled to maintain proper emissions control. It’s important to address this warning, because failure to refill the tank may lead to your vehicle going into reduced power mode and in some cases the car won’t start. You’ll need to switch it off to restart it.

Is it safe to drive with the AdBlue warning light on?

It’s not a major safety issue, but if you don’t top up, you’ll eventually run out of AdBlue and you won’t be able to start the car. When the warning light first comes on you’ll have plenty of time to refill.

What happens if I put AdBlue in the diesel tank?

Putting it directly into your fuel tank could cause expensive damage to your fuel tank, pump and injection system. If you start the engine it's likely to be an expensive write-off, so don’t touch the ignition. You’ll need to get the tank drained and the contents disposed of safely before you can refill it.