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Diesel Exhaust Fluid (DEF): Your Solution to Cleaner Fueling Exhaust

Discover the Benefits of Diesel Exhaust Fluid (DEF) for Clean and Efficient Fueling

Diesel engines have become a staple in various industries, thanks to their robust performance and fuel efficiency. However, one of the downsides of diesel fueling is the emissions produced by the engine. These emissions, such as nitrogen oxides (NOx), can harm the environment and human health. This is where Diesel Exhaust Fluid (DEF) comes in. In this article, we'll take a closer look at DEF, its benefits, and how it works.

What is Diesel Exhaust Fluid (DEF)?

Diesel Exhaust Fluid (DEF) is a solution made up of 32.5% urea and 67.5% deionized water. It is a clear, non-toxic, and non-flammable liquid that is used to reduce harmful emissions produced by diesel engines. DEF is sprayed into the exhaust system, where it breaks down NOx into harmless nitrogen gas and water vapor, which are then released into the atmosphere.

Why Use Diesel Exhaust Fluid (DEF)?

The primary reason to use DEF is to comply with government regulations on diesel emissions. In 2010, the U.S. Environmental Protection Agency (EPA) issued the Clean Air Act, which mandated the use of DEF in all new diesel engines to reduce emissions. DEF is also required by the California Air Resources Board (CARB) and the European Union's Euro 6 standards.

Apart from regulatory compliance, DEF offers several benefits to diesel engine owners. Using DEF can improve fuel efficiency, extend the lifespan of the engine, and reduce maintenance costs. DEF can also help maintain the performance of diesel engines by preventing the buildup of deposits and reducing the risk of engine failure.

How Does Diesel Exhaust Fluid (DEF) Work?

Diesel Exhaust Fluid (DEF) works by injecting a precise amount of the solution into the exhaust system, where it is sprayed onto a catalyst. The catalyst then breaks down the NOx into nitrogen and water vapor, which are released into the atmosphere. This process is called Selective Catalytic Reduction (SCR), and it is the most effective method of reducing emissions in diesel engines.

To use DEF, the engine must have a Selective Catalytic Reduction (SCR) system installed. The SCR system uses a dosing module to inject the right amount of DEF into the exhaust system, based on the engine's speed, load, and temperature. The DEF tank is usually located near the fuel tank, and it needs to be refilled regularly, depending on the engine's usage.

Why Choose Whatley Oil for Your DEF Needs?

At Whatley Oil, we understand the importance of clean and efficient fueling. That's why we offer a wide range of DEF products and services to help you comply with emissions regulations and keep your diesel engines running smoothly.

We offer DEF in various packaging options, including bulk delivery, tote delivery, and drum delivery. Our DEF products are of the highest quality, meeting the ISO 22241 standard, and we ensure that our customers receive only the best.

In addition to DEF products, we also provide DEF equipment and services to help you maintain your SCR system. Our team of experts can help you choose the right DEF equipment for your engine and provide installation and maintenance services to ensure that your system runs smoothly.


Diesel Exhaust Fluid (DEF) is a crucial component in reducing harmful emissions produced by diesel engines. By using DEF, you not only comply with government regulations but also enjoy the benefits of improved fuel efficiency, extended engine lifespan, and reduced maintenance costs. At Whatley Oil, we offer high-quality DEF products and services to help you keep your diesel engines running smoothly and efficiently. Contact us today to learn more about our DEF solutions.

Send your DEF questions our way!