Posts Tagged: DEF fluid

What Does DEF Fluid Do? A Complete Diesel Exhaust Fluid Guide

DEF Fluid Explained: What It Is, How It Works, and Where to Buy It Quick Summary • What is DEF? — Diesel Exhaust Fluid (DEF) is a precisely formulated solution of 32.5% high-purity urea and 67.5% deionized water. • Where you add it — You add it to a separate reservoir. The DEF filler cap is often blue to help distinguish it from the diesel fuel filler, although you should always verify the correct fill location in the owner’s manual. • What it does — The emissions system injects the … Read More