This article explains how DEF (Diesel Exhaust Fluid) works in conjunction with the SCR in diesel engines and how the EPA regulations affect truck owners.

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.

What is DEF? DEF, an acronym for Diesel Exhaust Fluid, is the trucking industry’s response to U.S. Environmental Protection Agency standards requiring all medium and heavy-duty diesel …

Apr 17, 2023 · DEF is made up of 67.5 percent deionized water and 32.5 percent high-purity urea. A quick internet search tells us there are roughly 100 American Petroleum Institute (API) …

Feb 10, 2025 · Learn everything you need to know about diesel exhaust fluid (DEF), how it works, and how to choose the best DEF fluid for your truck to keep it running smoothly.

Apr 13, 2018 · DEF is "Diesel Exhaust Fluid" and, as a matter of fact, modern diesels run just fine without it. DEF is instead concerned with what comes out of modern diesel engines. Diesels …

Diesel Exhaust Fluid (DEF) is used in diesel engines with SCR systems to reduce emissions. As the world's largest DEF producer, Yara offers the security of supply and reliable quality DEF.

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.

Feb 25, 2025 · But what exactly does DEF do in a diesel engine? Let’s break it down in detail. The Basics of DEF DEF is composed of 32.5% urea and 67.5% deionized water. This clear, non …