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.

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.

Apr 2, 2024 · Diesel exhaust fluid (DEF) is a blend of 32.5% urea and 67.5% deionized water, designed to reduce harmful emissions from modern diesel engines. Check our DEF guide.

Aug 19, 2025 · This article explains what diesel exhaust fluid, DEF for diesel trucks, its chemical composition, how the DEF system works, legal implications, maintenance, and more.

Dec 9, 2025 · Diesel Exhaust Fluid, often abbreviated as DEF, is a non-toxic, colorless, and odorless solution composed of purified water and urea. It is injected into the exhaust stream of diesel engines …

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) emissions. NOx is …

DEF keeps modern diesel trucks compliant and running at full power by reducing NOx emissions. Proper handling, storage, and maintenance prevent frozen fluid issues, contamination, warnings, and costly …

Aug 1, 2025 · DEF, short for Diesel Exhaust Fluid, is a non-toxic, colorless liquid made from a precise mixture of 32.5% high-purity urea and 67.5% deionized water. Unlike fuel additives, DEF is not mixed …

Jan 9, 2026 · Diesel Exhaust Fluid (DEF) is a recent and mandatory introduction to modern diesel engines, serving as an active component in the vehicle’s emissions control system.

DEF stands for Diesel Exhaust Fluid, a specialized solution designed to reduce harmful exhaust emissions from diesel engines. It consists of 67.5% deionized water and 32.5% urea, working to …