What is DEF/AdBlue (AUS 32) and Why is it Important?
AUS 32 stands for Aqueous Urea Solution 32.
If you own or operate a modern diesel vehicle, you’ve probably heard of DEF (Diesel Exhaust Fluid) or AdBlue, also known as AUS 32. But what exactly is it, why is it important, and how does it work? In this article, we’ll break it all down in simple terms.
DEF/AdBlue (AUS 32)
AUS 32 is called Diesel Exhaust Fluid in the American region (DEF), also called AdBlue in Europe, is a clear, non-toxic liquid made of:
- 32.5% high-purity urea
- 67.5% deionized water
This precise formula is what gives it the name AUS 32 (Aqueous Urea Solution, 32%). It is not a fuel additive. Instead, DEF is injected into the exhaust stream of diesel vehicles that use Selective Catalytic Reduction (SCR) technology.
Why is DEF/AdBlue (AUS 32) Needed?
Modern diesel engines are powerful and fuel-efficient, but they also produce nitrogen oxides (NOx) — harmful gases that contribute to air pollution and smog.
DEF/AdBlue plays a critical role in reducing emissions:
When sprayed into the hot exhaust, DEF breaks down into ammonia
The ammonia reacts with nitrogen oxides in the SCR system.
The reaction converts harmful NOx gases into harmless nitrogen and water vapor.
This process allows diesel vehicles to meet strict environmental regulations such as Euro 6, EPA 2010, and Bharat Stage VI.
Where is DEF/AdBlue Used?
Passenger Diesel Cars
Agriculture machinery/Construction equipment/Marine engines
Trucks and Busses
if your vehicle or equipment has an SCR system, it needs DEF/AdBlue
How to Handle and Store DEF/AdBlue?
To keep DEF effective and avoid damage to your vehicle’s system:
- Store in a cool, dry place (ideally between –11°C and 30°C).
- Use only high-quality DEF that meets ISO 22241 standards.
- Avoid contamination – even small impurities can damage your SCR system.
- Check expiry – DEF has a shelf life of around 12–18 months.
FAQ
Final Thoughts
DEF / AdBlue (AUS 32) is essential for modern diesel engines. It helps reduce emissions, protect the environment, and keep your vehicle compliant with international regulations.
By choosing a trusted DEF/AdBlue supplier, you ensure the highest product quality, engine safety, and peace of mind.
At JODEF, we provide premium AdBlue/DEF AUS 32 that meets international standards at competitive prices. Whether you need bulk supply or convenient 10L and 20L packaging, we’ve got you covered.
👉 Contact us today to learn more or place your order.