What is DEF?

Introduction to DEF

DEF stands for Diesel Exhaust Fluid, a non-toxic, colorless, odorless, and non-flammable fluid injected into diesel vehicles' exhaust systems to reduce harmful emissions.Also known as AdBlue, it's a mixture of 32.5% urea and 67.5% deionized water.

Composition of DEF

• Deionized Water (67.5%): Purified to remove minerals and impurities, ensuring SCR system efficiency.
• Urea (32.5%): A synthetic nitrogen-based compound that releases ammonia to neutralize NOx emissions.

How DEF Works

AdBlue is added to exhaust gas after combustion, not to fuel. The active ingredient, ammonia, reacts with and neutralizes NOx emissions before they enter the atmosphere, helping achieve Euro 6 compliance in heavy-duty engines.