Diesel exhaust fluid - Wikipedia
Diesel exhaust fluid (DEF; also known as AUS 32 and sometimes marketed as AdBlue[3]) is a liquid used to reduce the amount of air pollution created by a diesel engine. Specifically, DEF …
What is def fluid – Complete Guide, Causes & Fixes
Jan 4, 2026 · # What is DEF Fluid? The Complete Guide, Causes & Fixes Diesel owners know the dashboard warning lights can suddenly grab attention. If you drive a modern diesel, you’ll …
What is DEF? How it Works and Why it's Essential for Fleets | Geotab
Jul 17, 2025 · DEF's primary use is to chemically convert NOx into harmless nitrogen gas and water vapor. This process is crucial for meeting stringent environmental regulations and …
Diesel Exhaust Fluid (DEF) Guide: Uses, Risks & Storage
Jul 4, 2025 · Diesel exhaust fluid (DEF) is a small part of your vehicle, but it plays a big role in keeping engines clean and compliant. In this guide, we’ll answer the most common questions …
Diesel Exhaust Fluid Explained: What Is DEF & Why It Matters
Dec 9, 2025 · Learn what Diesel Exhaust Fluid (DEF) is, how it works, and why it’s essential for reducing emissions and improving diesel engine efficiency.
Diesel Exhaust Fluid: Everything You Need to Know
Feb 10, 2025 · Diesel exhaust fluid plays an important role in the emissions system on your diesel engine, but to better understand exactly what it does and why we need it, we need to provide a …
What is DEF? How Does DEF Fluid Work in Diesel Engines
Apr 2, 2024 · Diesel Exhaust Fluid (DEF) is a non-toxic, colorless liquid made of urea and deionized water. It’s injected into the exhaust stream of diesel engines to break down harmful …
What Is DEF and How Does It Work? - MotorTrend
Jul 29, 2024 · The heat from the exhaust converts the urea from the DEF into ammonia gas and carbon dioxide. The ammonia then breaks down the oxides of nitrogen, turning them into …
DPF vs DEF on Diesel Equipment: What’s the Difference
Jan 3, 2026 · DPF vs DEF: What's the difference? Learn how this filter and fluid work to prevent engine derates, warnings, and expensive downtime.
What is DEF and How Does It Work? | Diesel Dash Blog
DEF is not a fuel additive; instead, it is a precise mixture of urea and deionized water that is sprayed into the exhaust gas before entering the diesel engine’s SCR catalyst.