How Much Does Diesel Exhaust Fluid Cost Per Gallon?

The Clean Air Act of 1970 paved the way for the creation of the Environmental Protection Agency. The Environmental Protection Agency (EPA) has been constantly evolving and enacting laws to address the country’s environmental requirements for 46 years. For many years, owners of three-quarter and one-ton light-duty pickup trucks were not required to install additional smog equipment. All of that changed in 2008, when the Environmental Protection Agency mandated the use of diesel particulate filters on all three-quarter-ton and larger vehicles, as well as biannual smog testing that included a visual assessment of the truck to ensure the DPF parts were still there. The rules were tightened even more in 2010.

Many people believed that the age of enormous power and torque was finished, and they resolved to never buy another vehicle. However, something fantastic occurred, as well as the polar opposite. Americans have proven to be adaptable and resilient. Every manufacturer worked out a way to reduce NOx emissions while still producing more horsepower and torque than ever before. Strife yields bread, and bread yields innovation.

The application of selective catalytic reduction was the engineering breakthrough. To break down the created NOx into harmless nitrogen and water molecules, the great majority of these systems use diesel exhaust fluid (a mixture of urea and deionized water) injected into the exhaust system. Since the introduction of DEF (Diesel Exhaust Fluid), also known as after-treatment technology, in the exhaust, the manufacturer is free to create as much power as they like. The DEF is kept in a separate tank that is insulated and heated, with a blue filler cap to identify it.

Despite the effort around technology breakthroughs, there are still two factions of diesel guys out there: those who have accepted the EPA modifications and those who are still adamantly opposed to any limits. There has been a transition to older used diesel engines or remanufactured diesel engines that have been grandfathered in for individuals who are unable to accept the modifications. The purpose of this essay is to lay forth the cold hard facts concerning DEF and to educate the public on how to make better diesel operator decisions.

What exactly is Diesel Exhaust Fluid (DEF)?

DEF is a mixture of 67.5 percent deionized water and 32.5 percent urea from a chemical standpoint. Urea is a nitrogen chemical that, when heated, converts to ammonia and is employed in a range of industries. Although urea is technically produced from a urine waste, it is synthesized for mass manufacture. The American Petroleum Institute regulates most DEF products. Let’s look at the science of DEF in combination with exhaust. DEF is made up of two parts: (NH2)2CO and (NH2)2CO. When injected into hot exhaust gas, the water evaporates, leaving ammonia and isocyanic acid.

STEP 2: With water, the isocyanic acid breaks down chemically into carbon dioxide and ammonia:

STEP 3: At this step in the chemical reaction, ammonia will decrease nitrogen oxides in the presence of oxygen and a catalyst:

2(NH2)2CO + 4NO + O2 = 4N2 + 4H2O + 2CO2; 2(NH2) 2CO + 3NO2 = 7/2N2 + 4H2O + 2CO2; 2(NH2) 2CO + 3NO2 = 7/2N2 + 4H2O + 2CO2; 2(NH2) 2CO + 3NO2 = 7/2N2 + 4H2O + 2CO2; 2(NH2) 2CO + 3NO2

How Often Do You Need To Fill Up the DEF Tank?

This is a question that is specifically dependent on the diesel truck’s MPG and usage. The usual average light duty truck will require 2-3 gallons of DEF per 800 miles, regardless of the load, according to the OE manufacturer. Most new trucks with an average miles per gallon rating of 20+mpg, on the other hand, will travel 8,000-10,000 miles on a tank full of DPF (10 gallons). Each vehicle is different; for example, a Dodge Ram has a gauge that shows how much DEF is left in the tank, while a GM truck has a digital readout and a Ford truck has a basic low DEF indicator.

Fuel models for medium and heavy duty trucks will vary, but DEF usage will be around 2% of total fuel consumption, according to Cummins Filtration. One gallon of DEF is used for every 50 gallons of diesel fuel used. Here are some forecasts from our friends at Cummins Filtration for Medium and Heavy Duty Consumption:

Where can you buy DEF?

Don’t be tricked by thinking that DEF can be purchased just about everywhere. DEF is typically sold in large bottles holding numerous gallons of the substance at truck stops. If you’re in a pinch, some petrol stations will have DEF, but don’t bank on it. It is critical to note that if you do not refill an empty DEF tank, the engine will shut down automatically. Because DEF isn’t offered everywhere, you don’t want to be trapped anywhere with an empty tank. TravelCenters of America, Walmart, Target, Love’s Travel Shop, SAPP Brothers, Flying J Truck Stops, Petro Stopping Centers, and Pilot Travel Centers, O’Reilly’s, NAPA, and Advanced Auto are all common places to buy DEF. We’ve also put together a list of the most popular DEF manufacturers.

What are the Pros and Cons of a DEF Truck?

DEF has few drawbacks because it is a relatively straightforward technique. However, because the Diesel Particulate Filter (DPF) and Selective Catalytic Reduction (SCR) are prone to clogging, they can cause a slew of maintenance and repair concerns. These systems are intricately designed, and even a simple blocked filter can result in pressure and temperature differentials that influence the engine’s overall performance.

The only disadvantages of DEF are the higher initial cost, added weight, and the need for more storage space for an extra gallon of the fluid. Better fuel economy, more horsepower, more optimized combustion, fewer regeneration troubles, less engine wear, and it only emits nitrogen and water vapor into the air are some of the benefits.

Is emissions production really an important issue?

Whether it’s a major concern or not is debatable, given that all light-medium diesel engines built after 2008 must meet with EPA regulations. Smog, greenhouse gas emissions, and acid rain have all been linked to NOx emissions. The DEF converts NOx into pure nitrogen and water vapor as part of the Selective Catalytic Reduction system (SCR). Climate change is a contentious issue, but we can all agree that adding additional gasses to the atmosphere of any kind isn’t something we need.

Will DEF Lower My Fuel Mileage?

It is natural to believe that any EPA-mandated alterations to the diesel engine will be detrimental, but this is not the case. The big diesel makers learned that they could fine-tune the engine in whatever way they wanted, then let the SRC and DEF remove the particles. The engines are designed with performance in mind first, and then the SRC, DPF, and DEF are added as an afterthought to remove what is no longer required. Manufacturers have discovered that engines with SCR technology achieve better fuel mileage than engines with conventional internal pollution reduction systems. Fuel fed to the SCR provides an additional supply of components to burn. It is possible to increase fuel mileage by as much as 5% to 7%.

Has this new DEF Technology Ever Been Used Before?

DEF technology has been employed in agriculture, industry, and large-scale power generation in the country for decades. The premise is the same everywhere: urea combined with heat produces ammonia, which induces a chemical reaction that reduces NOx by 70% to 95%. In fact, nitrogen-released fertilizer accounts for 90% of urea production. It’s worth noting that automotive-grade urea has a far higher purity level than fertilizer-grade urea. If a lower-grade fertilizer, urea, is used in vehicle engines, the SCR may disintegrate, causing the engine to fail. It could even cause ECM sensors to issue an inaccurate DEF Tank Empty signal.

Does DEF Evaporate After A Period of Disuse?

Yes and no are the answers. With the valves wide open, the temperature at which DEF combines with NOx exhaust immediately out of the cylinder head is between 1400-1600 F. The chemical reaction occurs at substantially higher temperatures than those experienced on a hot summer day. For example, converting the DPF to ammonia and evaporating it would take two years at a steady temperature of 125 degrees F. However, because DEF is roughly 2/3 water, any temperature above 86 F risks some evaporation. Unless exposed to consistent hot climes, you won’t have to worry about a gallon or two of the stuff going bad or evaporating from inactivity.

Is DEF a Toxic and Harmful Chemical?

Urea, the active element in DEF, has been chemically produced since 1828, when German chemist Friedrich Wöhler used ammonium chloride to treat silver cyanate. Herman Boerhaave, a Dutch chemist, was the first to detect urea in urine in 1727. Urea is mostly employed in agricultural fertilizers, but it is also found in the chemical industry, explosives, lotions, skin creams, hair removers, plastics, dish washes, and fuel cells. Humans are not extremely poisonous to urea and, as a result, DEF. Urea can irritate the eyes, skin, and respiratory tract, but it is not dangerous. High quantities of urea in the blood can be dangerous to humans, however absorption of modest doses of urea, when accompanied by proper water intake, is not. In nature, urea can induce algal blooms, which can produce harmful fumes when it decomposes over its melting or heating threshold. When nitrites are mixed with certain oxidants, such as chlorides, they can create fires or even explosions.

What happens to the engine if the DEF Tank is empty?

The EPA now requires all diesel engine manufacturers to include a tiered warning system (internal gauges on the dash) that tells the driver how near the DEF tank is to being empty. The truck will stop working if you ignore the DEF warning. Some diesel engine manufacturers allow the engine to go into low-power mode, allowing the truck to “limp home” or limiting the number of times the engine can be turned over. However, the diesel engine would eventually fail to start. Treat the DEF tank as if it were a fuel tank; you don’t want to be stranded somewhere because you forgot to replace it.

Does DEF Have a Low Freeze Point?

At 12 degrees Fahrenheit, the normal 32.5 percent DEF solution begins to crystallize and freeze. When urea and water are combined in DEF, they both freeze at the same time. This is advantageous to the user because the DEF solution does not get diluted or too concentrated as the fluid thaws. The product’s grade is unaffected by freezing and thawing cycles. When DEF is frozen, it expands by 6.5 percent to 7% by volume. Freezing periods are accommodated by the packing.

What is the best method to keep DEF from freezing?

Keeping a gallon or two of DEF in your vehicle is totally safe, but it is not recommended. At 86 degrees Fahrenheit, DEF begins to degrade. It’s all too easy to forget about the DEF in the rear of your vehicle, and given enough hot days, the fluid can become unstable and degrade, but at a very slow rate. A diluted DEF without the 32.5 percent urea combination can be harmful to DEF and SCR, however this is a rare occurrence. As a result, on exceptionally cold days below 12 degrees Fahrenheit, DEF will freeze in the DEF tank. This is totally normal and will have no negative impact on the engine. The SCR systems are intended to give heat to the DEF tank, allowing the tank and related supply lines to thaw quickly.

Can I add anti-freezing solution to the DEF mixture to keep it from freezing?

DEF has a relatively specific formula consisting of 32.5 percent urea and water, but it also contains additional compounds in trace amounts to help stabilize the product. The precise chemical makeup of the mixture would be disrupted by an addition, lowering the NOx reduction characteristics. The DEF mixture’s ability to function effectively will be jeopardized by further blending, and the SCR system will be harmed.

How is the production of DEF regulated and can I make my own?

It is not advisable for direct consumers to make their own DEF. DEF is strictly regulated, has stringent standards for chemical purity, and comprises chemicals that are critical to the SCR system’s operation. DEF must be utilized with SCR systems and meet all ISO norms and API requirements, according to Caterpillar, Cummins, and Detroit Diesel, among others. The American Petroleum Institute (API) has a wholly voluntary program that confirms the chemical purity of DEF and that manufacturers fulfill ISO requirements. API Certification is achieved by all major DEF brands present on the consumer market.

What is the shelf life of DEF?

The batch of DEF will last around two years if it is stored at ambient temperatures of 75 degrees Fahrenheit with no large periods of exposure to heat above 86 degrees Fahrenheit. If a package of DEF is heated over an extended amount of time, the fluid will last about a year.

Who are the major manufacturers of DEF Fluid?

DEF Fluid is made by a variety of companies. “Oilmen Truck Tanks,” a website, has collected a list of 13 main manufacturers. DEF is available for $2-$3 per gallon at most big truck stops, auto parts stores, and convenience stores.

How can you determine the age of a container of DEF?

A manufacturers date can be found somewhere on every DEF package. It’s most likely near the bottom of the front of the packaging. This date code will reveal the precise date the batch was manufactured, as well as the age of the DEF bottle. A laser code is inscribed on the bottle of one gallon containers. A little date code is frequently placed on the product label of larger 2-5 gallon tanks. A larger label will be put on the side or top of larger DEF fluid drums (55 gallons or more) and totes (275-355 gallons). Reading a manufacturer’s code is difficult, as each one is slightly different. The batch number is usually represented by the first digit of the date code, and the next six digits reflect the date the batch was filled at the factory.

How do you identify a DEF Filling Pump Vs. a Diesel Fuel Pump?

A number of safeguards have been put in place to prevent diesel engine fuel from being injected into the DEF tank and vice versa. “The color “green” is the standard for diesel filling stations and pumps around the world. “The color “blue” has been chosen as the symbol for DEF fluid. DEF is dispensed by a normal 19 mm nozzle, while diesel fuel is dispensed through a 22 mm nozzle. As a last line of defense, the tank cap on almost all trucks should be a “brightly colored blue” to prevent diesel from entering the DEF tank.

What should I do if I accidentally dispense diesel fuel into the DEF?

First and foremost, do not be alarmed. Second, do not start the engine under any circumstances. If you don’t start the engine, putting diesel fuel in the DEF and vice versa (DEF in the fuel tank) will not hurt it. The SCR should detect the presence of a solution other than DEF in the tank and alert the driver through the dashboard ECM readout. It’s also crucial to avoid moving the vehicle. The distribution of fuel into the lines and into the SCR might be caused by moving the vehicle. Draining the tank while the vehicle is still in its original location is the best option. If the engine is started for even a short time, diesel fuel will destroy the SCR catalyst, which is highly expensive to replace and is no longer covered by the manufacturer’s guarantee. If DEF gets into the fuel system and spreads throughout the engine, it will eventually destroy the diesel engine. The DEF is incompatible with the gasoline system lines, which corrode with time.

What does DEF cost per gallon?

As if finding a clean spot to pump gas wasn’t difficult enough, diesel owners also had to worry about keeping their diesel exhaust fluid (DEF) tanks filled off. What happens if the treatment tank is completely depleted? We did the research and testing so you don’t have to.

Diesel veterans have long known how to deal with this issue. The following primer is intended for newcomers to diesel engines as well as gasoline-engine fans interested in learning more about life on the other side. DEF, commonly known as AdBlue or Blue DEF, is an elixir required to ensure that the exhaust from a diesel vehicle is as pleasant as an Alpine breeze. Those who refuse to listen to DEF risk severe consequences.

DEF is a fluid made up of urea and deionized water in a 1:2 solution that can be purchased at most service stations for $6 to $10 a gallon. To manage some pollutants, it’s stored in a reservoir separate from the gasoline tank and metered into the engine’s exhaust stream. The DEF vaporizes and decomposes into ammonia and carbon dioxide inside the exhaust pipe. Inside the vehicle’s selective catalytic reduction (SCR) catalyst, these two chemicals react with oxygen and harmful nitrogen oxides. Nitrogen, water vapor, and carbon dioxide are produced as a result of this process.

Make certain that any DEF you buy is labeled to meet ISO (International Organization for Standardization) 22241 requirements. While DEF does not deteriorate with age, it can freeze, so keep your supply somewhere warm. Because the contents stay in solution, no shaking or mixing is required prior to use.

Is DEF fluid expensive?

As a result, in an SCR-equipped car, the exhaust gas from the engine passes through a particle filter first, catching all of the soot and ash produced by burning a relatively dirty fuel. That eliminates the “rolling coal” feature of old diesel engines, which made them unpopular in the United States in the 1960s, 1970s, and 1980s.

The exhaust gas passes via a nozzle that sprays diesel exhaust fluid into the stream of gases after it passes through the particulate filter. DEF is created from deionized water and urea in its purest form. Yes, urea is found in urine — please stop laughing — but this is a refined form of the molecule that is primarily employed in agriculture as a fertilizer component.

The heated exhaust gas and DEF are then sent into the catalytic converter, where the urea in the DEF and the exhaust gas react with a range of metallic compounds to convert nitrogen dioxide and monoxide to nitrogen and water. Nitrogen is the most abundant element in the air we breathe and is completely safe for the environment. Water is just that: water.

This is certainly a simplified description of how SCR works, but other from the extra step of injecting urea into the exhaust stream, it’s very similar to how your gasoline-powered car’s catalytic converter works. To minimize emissions, most modern diesel engines employ SCR in conjunction with exhaust gas recirculation and a diesel particulate filter (DPF).

Exhaust gas recirculation, or EGR, is a typical procedure that reduces the quantity of unburned fuel in a vehicle’s exhaust fumes. It is utilized in nearly all current ICE engines. EGR has the disadvantage of reducing vehicle performance and fuel economy, as well as adding another complex system to an already complex machine.

As a result of EGR’s flaws, several firms are removing it from their engines and replacing it with somewhat more DEF to treat the exhaust gases, achieving similar results without sacrificing performance or efficiency.

Isn’t all of this appealing? SCR and DEF, on the other hand, are not universally seen as beneficial. I mean, you have to keep it filled all the time, right? Isn’t it also expensive? Nope. Every time you replace your oil, a usual tankful of DEF will need to be refilled. It’s also largely water, so it won’t break the bank. A 2.5-gallon pack of BlueDEF (as opposed to the stuff your dealer may sell) will put you back about $80.

Why is diesel exhaust fluid so expensive?

Because of its high urea content and the higher quality of urea required to make DEF, urea prices frequently dictate the cost of DEF. Urea prices increased to $442 per ton in June, up from $380 in May, according to Jobbers World.

How expensive is DEF?

Diesel exhaust fluid (DEF) costs fell a penny per gallon at the pump between February and March of this year, while bulk tote prices jumped two cents per gallon.

The average U.S. DEF pump price fell by a penny to $2.74 per gallon between February and March, according to Integer Research, which tracks DEF prices through its DiscoverDEF website. This is the continuation of a marginal downward trend, the firm said, with pump prices now down two cents per gallon since December of last year.

“Since the first station opened in October 2011, there has been no change in the pump price in Canada,” Chris Goodfellow, an emissions analyst at Integer, told Fleet Owner.

Pilot Flying J, which has set the per gallon price at CAN 80 cents per litre – around $3.16 per gallon in US currency – runs the five stations now supplying DEF in Canada, he added.

“DEF is generally more expensive north of the border, and this pump price is roughly 11% higher than the national average,” Goodfellow explained.

However, between February and March, bulk tote costs rose two cents to $2.02 per gallon, however Integer noted that some fleets receiving bulk DEF deliveries to permanent storage tanks saw a small price drop.

“As new locations open up and localized competition plays a stronger role in price strategy, the market for DEF at the pump is growing more competitive by the day,” Goodfellow explained. “As a result, suppliers that previously priced DEF on a nationwide level are now doing it on a state-by-state or even location-by-location basis, and we’ll see more of this as volumes grow.”

Even if the cost trends are trending in opposite directions, it’s worth noting, according to Goodfellow, that owner-operators still save nearly a third on DEF when switching from truck stop pump to tote supply.

By the end of March, additional 21 truck stop locations had added DEF pumps to their fuel islands, increasing the total number of DEF refueling facilities in the United States to 446.

Will DEF freeze in my truck?

DEF, whether in storage tanks or equipment, can freeze and cause problems. When temperatures dip below 12°F, DEF begins to crystallize and ceases to function properly. Because of the precise ratio utilized, the entire mixture can freeze and thaw together like water and ice.

Why does DEF cost so much?

DEF prices have risen dramatically in the last month, following a consistent increasing trend throughout 2021. Rising urea prices are to blame for the sharp spike. In addition to being the main element in DEF, urea, which is made from ammonia, has important uses in fertilizer. With a few exceptions, prices normally range from $200 to $300 per ton, but in June, prices soared over $400 per ton, and have since climbed to a stunning $600 per ton.

There are three reasons why the price of urea (and thus DEF) has grown so quickly:

  • Increasing commodity prices have pushed up all costs this year, including food, metals, energy, and chemicals like urea. Urea prices have risen this year, similar to oil prices, as a result of the post-pandemic rebound.
  • Hurricane Ida recently wreaked havoc on several of the country’s biggest manufacturing factories on the Gulf Coast, causing delays across the country. Furthermore, New Orleans is a significant urea trading hub, leading prices to climb.
  • Importing urea from other countries is expected to become more expensive in the future, according to markets. The recent energy crisis will dramatically increase the cost of producing urea in Europe, which is a major producer. Demand for fertilizer and DEF isn’t going away, therefore restrictions on European imports will have a substantial impact on DEF prices in the coming months.

A combination of circumstances, including increased steel prices affecting totes, resin prices affecting jugs, and a driver scarcity affecting freight, has resulted in a severely constricted DEF market. One of the country’s largest DEF suppliers was compelled to declare force majeure. Operational flaws can lead to widespread delivery problems, wreaking havoc on supply systems.

When practicable, increasing storage capacity is one of the greatest ways to manage the supply gap. Having extra supplies on hand allows for longer delivery lead times, ensuring that your equipment remains functioning. Because a substantial amount of DEF pricing is dictated by logistics rather than commodity rates, increasing storage may help you lower your total DEF cost, depending on your current storage capacity and supply schedule.

Is there a Diesel Exhaust Fluid shortage?

You may have never heard of urea, but the chemical compound’s worldwide shortage may bring Australia’s supply chain to a halt in a matter of weeks.

The molecule, which is a vital ingredient in the diesel exhaust fluid AdBlue and a major component in fertilizer, is in low supply around the world.

The main cause of the scarcity is China’s prohibition on urea exports, which previously supplied 80 percent of Australia’s urea supplies. This is because the price of fertilizer has risen dramatically, and China wants to curb the rate of increase.

However, because urea is sprayed into the exhaust systems of modern diesel cars to lower emissions, which is a necessity for trucks, passenger vehicles, and tractors, this could inadvertently take many of Australia’s trucks off the road.

So, what is urea, and how serious is the supply chain disruption in Australia?

What does DEF do to diesel exhaust?

We get a lot of questions about DEF and how to use it effectively on your forecourt, so we asked the expertise of Danny Seals, a forecourt solutions expert, to provide us with some simple answers.

What is DEF?

DEF is a urea-water solution that is injected into the exhaust stream of diesel automobiles to convert NOx gases (harmful emissions) into nitrogen and water. Vehicle manufacturers introduced a Selective Catalytic Reduction (SCR) technology to meet EPA emissions limits in 2010. This is a strategy to achieve the requirements without sacrificing engine performance or fuel economy. DEF isn’t a fuel additive, and it’s kept in its own tank.

Who needs DEF, why?

DEF is required for medium and heavy-duty vehicles equipped with diesel engines manufactured after 2010. To meet emissions rules, the vehicle is configured to inject DEF into the exhaust stream. The engine performance will be diminished and lower speeds will be imposed if the vehicle is allowed to run out of DEF.

What are the different delivery modes of DEF?

DEF is available in a variety of forms. A driver can purchase jugs/containers in a variety of sizes. This necessitates the driver physically transferring the DEF into the car. When installed, DEF can also be dispensed into the vehicle using a fueling dispenser.

Which retailers should offer DEF and what indicators can they use to decide?

Because there is such a vast population of automobiles on the road, DEF is an excellent product for all c-stores to offer. Retailers who sell diesel at their gas stations can utilize the volume sold to estimate the number of diesel customers they have. DEF is required by the majority of today’s heavy-duty trucks. Locations with a separate large truck filling station might think about putting DEF in the dispensers. Because they buy DEF in quantity to keep in their tanks, this results in higher profit margins. Some places that sell a lot of diesel on their forecourt should also consider a dispenser option.

How can Gilbarco help retailers get into DEF?

Since the inception of DEF requirements, Gilbarco has been the industry leader in DEF dispensers. Over the years, we’ve worked with large stores to provide dispenser functionality, and we’ve established the industry standard for this service. Gilbarco assists merchants in entering the DEF dispensing market by providing factory-installed options and retrofitting existing dispensers where DEF is stored in bulk.

Is Diesel Exhaust Fluid all the same?

This is a question that is being asked more frequently, and the answer is a little tricky because it is based on the definition of what is Diesel Exhaust Fluid. To be labeled as a Diesel Exhaust Fluid (DEF), a product must meet the following requirements:

  • ISO 22241—An international standard that specifies the quality criteria for DEF, including production, storage, and distribution—must be met. The ISO 22241 standards govern the manufacturing, processing, and transportation of DEF. The following are the main points:
  • The urea concentration in diesel exhaust fluid (DEF) must be 32.5 percent by weight. Because it has the lowest freezing temperature, 12°F, this concentration was chosen.
  • The maximum levels of contaminants like calcium, as well as different metals including iron, copper, zinc, and aluminum, are explicitly stated. These restrictions are exceedingly low in order to ensure that the SCR system operates reliably.
  • This definition excludes the use of agricultural urea grades and needs water that has been cleansed through distillation, deionization, or other means.

If a product does not meet the ISO 22241 requirements, it cannot be considered a Diesel Exhaust Fluid by definition (DEF).

With a growing market, there will be an increasing number of unauthorized items on the market claiming to be DEF but actually being a urea solution. The only way a product would be unlicensed is if it did not comply with the ISO and API DEF standards. The problem with these goods is that they will almost certainly cause SCR systems to fail. Some of these failures may be instantaneous, while others may take days, weeks, months, or even years to notice before failing, but the SCR system will collapse prematurely.

Even today, there is much discussion on blogs about how some independent DEF blenders that have registered with the API and follow the ISO 22241 criteria do not test every batch and that certain batches do not fulfill the very demanding ISO 22241 standards.

This can happen for a variety of reasons, but one of the most common is that the urea used is not Pharmaceutical Grade Urea, but rather Agricultural Grade Urea, which contains impurities such as aldehydes and high levels of biuret in comparison to ISO 22241 standards, which are poisonous to SCR systems. Water purity is another place where severe errors in DEF manufacture will occur. The production of DEF necessitates the use of de-ionized water. The presence of even the tiniest amount of metals/contaminants in the water will cause the fluid to fail to fulfill the ISO 22241 specification, and these elements will poison the SCR system. Calcium, Zinc, Magnesium, Iron, Chromium, Nickel, Sodium, and Potassium are examples of elements.

In average tap water, all of the above are present in variable amounts and concentrations.

To summarize, only products that comply with the ISO 22241 regulation and are API-licensed can be named Diesel Exhaust Fluid…all other products are simply Urea Solutions in varying concentrations and cannot be labeled Diesel Exhaust Fluid.

To take it a step further, only those suppliers with long-term supply agreements with Urea producers, particularly Pharmaceutical Grade Urea, will be able to keep the market supplied with Diesel Exhaust Fluid, so choosing the right Supplier and Distributor is critical to ensuring that you have product to keep your fleet and equipment moving.

How much DEF is used per gallon of diesel?

The amount of DEF used will be about 2% of the total amount of diesel used. Another way to think about it is that DEF and diesel will be consumed in a 50:1 ratio. (One gallon of DEF is used for every 50 gallons of diesel fuel burnt.)