A Brief Overview of Diesel Exhaust Fluid and Its Purpose

The substance known as diesel exhaust fluid is added to diesel fuel to reduce harmful emissions, which is beneficial for air quality. The substance breaks down emissions into water and nitrogen so they can be safely dispersed into the air. Most diesel-fueled vehicles that were manufactured within the past four years require DEF to work as efficiently as possible.

Components of DEF

The fluid is a relatively simple one, consisting only of deionized water and a combination of carbon dioxide and synthetic ammonia. Those two chemical components combine to form synthetic urea. Deionized water is similar to distilled water in that these liquids have had the minerals removed, but they are still chemically different.

Where DEF Is Bought and Stored

Unlike fuel additives, these products are sprayed into the exhaust of passenger vehicles instead of poured into the fuel tank. Passenger cars and commercial vehicles like semi trucks can have a container for DEF on the vehicle itself. Commercial drivers generally pour the substance into this container from dispensers at fueling stations. Passenger car owners who want to buy DEF can find it at auto parts stores and some other stores that sell fluids for vehicles.

Diesel-Powered Vehicles in the USA and Europe

In the United States, the percentage of diesel-powered passenger vehicles is very small. Most of these vehicles are large pickup trucks and foreign car models. In contrast, diesel models account for about half of the passenger vehicles in Europe.

The Emissions Problem

With emissions continuing to be a problem, however, some European countries are trying to phase out gas-powered and diesel-powered vehicles over the next several years. A similar push is on in California, which has the strictest emissions standards of any state. The Los Angeles area was once infamous for its smog and air pollution.

It will probably be a very long time if these measures become widespread, if ever. Vehicle manufacturers continue to design products that produce fewer harmful exhaust emissions, as they did when adding the catalytic converter. That equipment became mandatory in the United States in 1975. Including containers for DEF is another way to keep emissions lower.