What Is Diesel Exhaust Fluid?

If you are considering converting your fleet (or your personal vehicle) to diesel, you’ll need one more consumable in order to run your vehicle: Diesel Exhaust Fluid or DEF.

It’s not a fuel additive, and is added to a separate tank that’s easy to refill (usually with a blue cap.) Therefore, it never comes in contact with the fuel itself, and generally doesn’t impact fuel mileage.

DEF is a solution of 67.5% de-ionized water and 32.5% urea, a compound of nitrogen that, when heated, turns into ammonia. Urea is also used as agricultural fertilizer, animal feed, cleaning products, plastics, and pharmaceuticals.

Using the Selective Catalytic Reduction (SCR) system now required on all diesel vehicles, the catalytic converter causes the water to evaporate and the urea to convert to ammonia on a catalyst. Ammonia molecules then react in the exhaust stream, and neutralize the NOx molecules. Nitrogen and water are now released into the atmosphere. SCR systems are calibrated to use the 32.5% urea/67.5% concentration.

Why Do I have To Have DEF?

Since 2008, the EPA has required diesel truck manufacturers to implement SCR technology in vehicle.  SCR technology is designed to reduce nitrous oxides (NOx) emissions. OEM companies also began incorporating SCR into their engines without changing the engine design or operations.

Nearly all diesel vehicles made since 2010 have SCR, requiring the use of DEF.  This includes pickup trucks, heavy-duty trucks and vans, as well as several European diesel luxury cars and SUVs. As of 2014, off-road vehicles like those used in agriculture and construction, are also required to have SCR and use DEF for emissions reduction.

What To Know About Diesel Exhaust Fluid

• It’s not flammable, nor becomes toxic at any temperature. If you get some on your skin or in your eyes, wash with soap and water.

• It’s easy to carry some in your vehicle in case you run low.

• DEF has been shown to improve fuel economy by about 5%, and uses the diesel fuel more efficiently.

• You won’t have to refill your DEF tank every time you fill up with fuel. Typically, the consumption rate is 2% to 4% of diesel consumption. About 2 to 4 gallons of Diesel Exhaust Fluid are injected into the exhaust stream for every 100 gallons of diesel. DEF tank is usually between 15 and 20 gallons, so you’ll refill it about every 5,000 to 6,000 miles.

• DEF is available nationwide at retail stores and truck stops nationwide (and even Amazon sells it). It’s available either in ready-packaged containers (like anti-freeze or brake fluid) or at the pump. During emergency situations, should you run low of Diesel Exhaust Fluid, Specialty Fuel Services can deliver it to your site.

• Although it doesn’t have a specific shelf life, (extreme temperatures can affect its usefulness) DEF shouldn’t be used if it’s over a year old.

• Store DEF between 40F and 80F to maintain its shelf life. Storing it above 86F will cause hydrolysis and reduce its effectiveness and shelf life. Storing DEF below 11F causes crystallization in the product. However, a freeze-thaw cycle will not affect effectiveness.

• DEF doesn’t impact fuel mileage, but has been shown to improve fuel economy by about 5%.

Diesel Fuel Delivery

Fuel is an essential for any business that has a fleet, or uses an on-site generator in the event of a power failure. If your facility uses diesel, you may be wondering, “is there diesel fuel delivery near me?”

Getting an adequate supply of diesel fuel delivered to your facility isn’t enough to keep your fleet running, especially after an emergency. Add Diesel Exhaust Fluid to your fuel delivery to make sure you don’t run low, especially at the worst possible time. Advance fuel planning with Specialty Fuel Supply relieves the concern about “fuel delivery near me” by providing fresh, available fuel on demand, and DEF to go along with it.

Call us at 1-866-445-5508, send us an email us at [email protected], or use our online contact form to make sure your diesel fuel delivery is scheduled. Centrally located with strategic fuel reserves throughout the US, Specialty Fuel Services can deliver emergency fuel and equipment anywhere. Add us to your disaster recovery and business continuity plan to ensure bulk fuel delivery (including DEF) to your location anytime you need it.