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Diesel Exhaust Fluid

If you’re new to having a diesel truck or heavy equipment, there’s a critical additive you need to know about. It’s called DEF fuel or Diesel Exhaust Fluid (DEF). This additive is also called aqueous urea solution 32% or AUS 32. It’s made from 32.5% urea and 67.5% de-ionized water. Read on to find out everything you need to know about the DEF in your DEF system.

What Is DEF For Diesel?

If you’re just acquainting yourself with the world of diesel engines, you might be wondering, what exactly is DEF or Diesel Exhaust Fluid? DEF, also known as Aqueous Urea Solution 32% (AUS 32), is a crucial additive for diesel-powered vehicles and heavy equipment. It’s composed of 32.5% urea and 67.5% de-ionized water. Let’s delve into the details to uncover the significance of DEF in your engine’s exhaust system.

What Is DEF Fluid Made Of?

DEF is formulated from a precise mixture of 32.5% synthetic urea and 67.5% de-ionized water. This carefully balanced blend plays a pivotal role in reducing harmful emissions from diesel engines. The urea component undergoes a chemical reaction when introduced into the exhaust stream, breaking down nitrogen oxides into harmless nitrogen and water vapor.

What is the Purpose of Diesel Exhaust Fluid?

In 2010, the EPA required diesel engines to reduce their production of (NOx) nitrogen oxides. That reduction is accomplished with the additive Diesel Exhaust Fluid (DEF).

This fluid reduces NOx and air pollution. So it helps heavy machinery and trucks operate within the federal emissions guidelines.  From 2010, heavy-duty diesel trucks and equipment had a diesel tank and an additional diesel exhaust fluid tank.

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What is Selective Catalytic Reduction?

To understand DEF, it helps to start with understanding Selective Catalytic Reduction (SCR).

SCR is currently the most effective option on the market for dissolving dirty gases, NOx, and particles that are released through your truck’s or heavy equipment’s diesel exhaust. Though the technology has been around for decades, in 2010, SCR systems became a national requirement for all new diesel models.

For SCR to work, a single liquid-reductant agent is necessary: Diesel exhaust fluid. DEF, a combination of synthetic, vehicle-grade urea, and de-ionized water, are injected into your truck or big equipment’s exhaust stream. Here, it breaks down harmful emissions into non-hazardous nitrogen and water, reducing emissions by up to 90%.

What Does DEF Fluid Do?

In 2010, the Environmental Protection Agency (EPA) implemented stringent regulations to curb nitrogen oxide (NOx) emissions from diesel engines. DEF steps in as the solution. When injected into the exhaust system, DEF reacts through a process called Selective Catalytic Reduction (SCR). This reaction converts NOx, a harmful pollutant, into nitrogen and water, effectively mitigating environmental impact.

Diesel Exhaust Fluid Purpose

The primary purpose of Diesel Exhaust Fluid is to facilitate compliance with federal emissions standards. By substantially reducing NOx emissions, DEF ensures that heavy machinery and trucks meet the stringent guidelines set by the EPA. This means your diesel-powered vehicle not only operates efficiently but also contributes to a cleaner environment.

What Is DEF For Trucks?

For heavy-duty diesel trucks, DEF is a game-changer. Alongside the conventional diesel tank, these trucks are equipped with an additional tank dedicated to holding DEF. This two-tank system ensures that your vehicle remains environmentally conscious without compromising its performance.

What Is DEF Fuel Used For?

DEF fuel is specifically engineered for one crucial function: to aid in emissions control. It’s not a fuel in the conventional sense, as it doesn’t contribute to the combustion process. Instead, DEF works in tandem with SCR technology to neutralize harmful emissions, enabling your diesel engine to meet stringent environmental standards.

How Much Does DEF Weigh?

DEF’s weight is an essential consideration for vehicle operators and fleet managers. A gallon of DEF typically weighs about 9 pounds (4.1 kilograms). This information proves valuable when planning for fueling and transportation needs, ensuring that your vehicle is equipped with the right amount of DEF for its journeys.

Frequently Asked Questions About DEF

If you are new to SCR and DEF vehicles, you probably have questions. Here are the ones we get asked most often:

1. How Often Do You Have to Add Diesel Exhaust Fluid?

2.5 gallons of DEF will last approximately 800 miles on the road. That means, 1 gallon of DEF will last about 300 to 500 miles. You can figure, for every 50 gallons of diesel, you’ll need 1 gallon of DEF. One important note, make sure you don’t allow your DEF to go completely dry. Avoid running out of DEF by securing a reliable bulk fuel supplier or installing a DEF tank in your yard or job site.

2. What Happens When You Run Out of Diesel Exhaust Fluid?

All new vehicles are equipped with gauges and/or lights to alert you when DEF is low. If DEF is not replaced, an emergency light will be triggered, and engine speed will be reduced to as little as five miles per hour.

To be prepared, it’s smart to carry a bottle in your truck, so you don’t get stuck driving slow on the shoulder of the highway. It’s also good to know that diesel exhaust fluid is nontoxic. So for you, that means once you have some on hand, you or your fleet’s drivers, can readily replace DEF, as needed.

No time to pick some up? Ricochet Fuel provides wet hosing services to keep your team moving when it counts.


3. Where Can I Find DEF?

If you’re searching for diesel exhaust fluid near me in the DFW area it’s simple. DEF is available right at the pump at Ricochet Fuel’s Euless location, seven days a week, 24 hours a day. In addition, Ricochet Fuel offers 2.5-gallon jugs, 55-gallon drums, and 330-gallon totes, and for even larger jobs, loaned bulk tanks with electric dispensers.

4. How Much Does DEF Cost?

The price varies depending on the quality and quantity of DEF you need to cover your fleet. Contact Ricochet Fuel today to learn more about pricing options.

5. Can I Switch Diesel Exhaust Fluid Suppliers?

Yes, you can. And if you have any remaining fluid in the tank, just run it as low as possible before filling up again. Since DEF is pure chemical, your tank doesn’t need to be cleaned out. That is unless you think it might be contaminated.

More Diesel Exhaust Fluid Tips
  • If you are storing DEF containers for maximum shelf life, keep temperatures between 40 and 80 degrees. With proper storage, DEF can last for up to two years.
  • Don’t worry about extreme heat or cold. DEF will not freeze in your vehicle and won’t dissolve in heat unless exposed to excessive heat for years.
  • Find a reputable source like Ricochet Fuel. Just like any fuel, DEF has precise industry requirements. As the number of vehicles requiring DEF grows, unlicensed sellers will continue to try to skirt regulations.
  • Don’t be fooled by market-cutting low prices. Instead, buy DEF that’s safe and effective.
  • Carry a gallon in your truck, so you never get stuck.
  • Keep a funnel on hand to make it easier to add from a gallon jug.
Your Source For DEF

For all your DEF needs in the Dallas-Fort Worth area, Ricochet Fuel offers pumps, nozzles, meters, and convenient pick-up and delivery options. With over 30 years of providing fuel solutions for companies nationwide, Ricochet Fuel is your top-rated fuel distribution company for DEF. For more information, contact Ricochet Fuel today.

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