Diesel exhaust fluid (DEF) is a liquid used to reduce the amount of air pollution created by a diesel engine. Specifically, DEF is an aqueous urea solution made with 32.5% urea and 67.5% deionized water. DEF is consumed in a selective catalytic reduction (SCR) that lowers the concentration of nitrogen oxides (NOx) in the diesel exhaust emissions from a diesel engine. DEF is also known as AUS 32 and marketed as AdBlue.
DEF is made up of deionized water and urea. These substances help turn nitrous oxide, a harmful type of emission from diesel engines, into water and nitrogen, two everyday substances that make up the air we breathe. Essentially, DEF is a key ingredient in starting the chemical reaction that keeps dangerous gases produced during diesel engine operation out of our environment.
Some additional facts about DEF include:
- DEF is a consumable fluid that needs to be added to diesel vehicles.
- DEF is used in SCR systems, which are increasingly commonplace in diesel engines.
- SCR systems using DEF are used by several brands of diesel vehicles, including Peugeot, Citroën, and DS Automobiles brands, Daimler AG, and UD Trucks.
- DEF is a ubiquitous component of almost every type of diesel-powered engine used in the United States.
- DEF is a mixture of 67.5% deionized water and 32.5% urea.
In summary, DEF is a liquid used to reduce air pollution created by diesel engines. It is an aqueous urea solution made with 32.5% urea and 67.5% deionized water, and it is consumed in a selective catalytic reduction (SCR) that lowers the concentration of nitrogen oxides (NOx) in diesel exhaust emissions. DEF is made up of deionized water and urea, and it helps turn harmful emissions into water and nitrogen. DEF is a consumable fluid that needs to be added to diesel vehicles, and it is used in SCR systems that are increasingly commonplace in diesel engines.
