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 …

Jul 29, 2024 · Diesel exhaust fluid, or DEF, is a key component in lowering pollutants emitted from diesel engines, helping to improve efficiency and reduce emissions.

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 …

Aug 1, 2025 · Diesel Exhaust Fluid (DEF) is essential for reducing emissions in modern diesel engines. How it works, and why it's critical.

Nov 21, 2025 · Whether you’re running a Power Stroke, Duramax, or Cummins, the DEF system controls emissions, protects your aftertreatment, and keeps your truck out of limp mode. When …

Apr 2, 2024 · Diesel engines equipped with Selective Catalytic Reduction (SCR) systems require DEF to reduce nitrogen oxide (NOx) emissions. If you don’t use DEF fluid, the SCR system …

Mar 18, 2025 · DEF is a non-toxic solution made up of 32.5% urea and 67.5% deionized water. It’s injected into the exhaust system of diesel engines to reduce nitrogen oxide (NOx) …

SCR (Selective Catalytic Reduction) technology, which uses DEF, was developed to convert harmful NOx into harmless nitrogen and water vapor. Without DEF, your diesel engine would …

Diesel Exhaust Fluid (DEF) is essential for reducing NOx emissions in modern diesel trucks. Learn how DEF works with SCR systems, why it matters for compliance, and how to maintain …

Aug 27, 2025 · Diesel Exhaust Fluid (DEF) is a crucial emissions solution that breaks down harmful pollutants. This guide explains what DEF does, how it works, and why proper usage is …