Builders settled on SCR technology for large-scale deployment. SCR uses a reducing agent which contains urea and water. DEF is injected upstream into the exhaust, converting NOx to simple gases. SCR technology was first adopted in an automotive application in by Nissan Diesel.
Since that time SCR technology has been implemented worldwide. So what year did chevy start using DEF? What about GM? Well Duramax engines have been a mainstay technology for Chevrolet and GMC since first installed in Duramax diesel has been an option across a complete line of light and medium-duty trucks, cars, and Duramax is a cooperative undertaking between General Motors and Isuzu. This version introduced advanced emission controls, including diesel exhaust fluid injection.
There was considerable scrutiny when Duramax released the LML version. The implementation of SCR systems demands a constant flow of diesel exhaust fluid. However, it was discovered the technology produced better than expected fuel economy. DEF was not costly, and owners were enjoying a better performance from their Duramax engines.
The Cummins Dodge diesel has been in continuous manufacture since Clessie Cummins a local mechanic first cultivated the technology in By , Cummins had conquered a substantial portion of the worlds heavy-duty truck engine market. Due to increased regulations, Cummins purchased Nelson Industries an emissions subsidiary and changed the name to Cummins Emission Solutions. Starting with the 6. SCR became a standard technology for the engine starting from to SCR was called for on every Cummins diesel beginning with the model year.
Cummins Industries has expanded their own Urea Dosing Technologies to facilitate emission controls across a vast product line.
It turns out that Americans truly do adapt and overcome. Every one of the manufacturers figured out a way to cut down on the NOx levels all the while making more horsepower and torque than ever before.
Innovation is bread out of strife. The engineering breakthrough came through the use of the selective catalytic reduction. The vast majority of these systems use diesel exhaust fluid mixture of urea and deionized water sprayed into the exhaust system to break down the generated NOx into harmless nitrogen and water molecules. Since the DEF Diesel Exhaust Fluid is introduced in the exhaust, also called after-treatment technology, the manufacturer is free to build as much power as they want.
The DEF is stored in a separate tank which is insulated and heated and is marked by a blue filler cap. Still there are two factions of diesel guys out there; those who have accepted to the EPA changes and those who are still vehemently against any regulations whatsoever despite the work around technological advancements. For those not willing to accept the changes there has been a shift to older used diesel engines or remanufactured diesel engines that have been grandfathered in.
This article aims to go over the cold hard facts about DEF and educate the populace into making smarter diesel operator decisions. From a strictly chemical disposition DEF is a mixture of Urea is a compound in Nitrogen that turns to ammonia when heated and is used in a variety of industries.
Urea is technically derived from a byproduct of urine but for mass production purposes it is synthetically made. Lets take a look at the science behind DEF when mixed with exhaust. Chemically, DEF is firstly comprised of NH2 2CO; and when injected into the hot exhaust gas the water evaporates leaving ammonia and isocyanic acid.
That question specifically depends on miles per gallon and usage of the diesel truck in question. No matter how heavy the load, according to the OE manufacturer, the typical average light duty truck will consume gallons of DEF per miles. For every 50 gallons of diesel fuel burned you will use 1 gallon of DEF. DEF is mostly sold at truck stops in big jugs containing multiple gallons of the stuff. We have also compiled a list of the most popular manufactures of DEF here.
There are very few cons with DEF as it is a fairly simple procedure to deal with. These systems are complicated in design and a simple clogged filter can cause pressure and temperature differentials that can affect the whole performance of the engine. The only cons to DEF include the additional upfront cost to the truck, added nominal weight and some additional room to store an extra gallon of the fluid.
The pros are better fuel economy, increased horsepower, more optimized combustion, fewer regenerations issues, less wear on the engine and in addition it only releases nitrogen and water vapor into the air. Whether it is a big deal or not is not really not up for debate considering all light-medium diesel and up have to comply with the EPA Regulations.
NOx has been blamed for smog, a rise in greenhouse gasses and acid rain. It is only natural to think that any EPA induced changes to the diesel engine is necessarily a bad one however it is quite the contrary. The major diesel manufacturers discovered it can fine tune the engine anyway it deems fit then allow the SRC and DEF to remove the particulate.
Manufacturers have found that engines containing SCR technology oftentimes get better fuel mileage compared with other smog reduction internal systems. Fuel mixed in with the SCR finds an added source of elements to burn.
DEF technology has been used for decades in the country in agriculture, industrial and large scale power generation applications. It is important to note that automotive-grade urea is of a much higher grade purity than fertilizer urea. If a lower grade fertilizer urea is used in automotive engines you risk disintegration of the SCR and possible ruin the engine. The answer is yes and no. The temperature at which DEF combines with NOx exhaust right out of the cylinder head with the valves wide open is between F.
Diesel Exhaust Fluid DEF consumption is measured as a ratio of diesel fuel use, normally termed the "dosing rate" or "treat rate". Feedback from a number of fleets suggests that the dosing rate is slightly lower than originally predicted by manufacturers, at around 2. The price of Diesel Exhaust Fluid DEF will depend on your location, supply method and the volume of fluid that you purchase.
Packaged supply, which comes in 1, 2. Bulk volumes, which are delivered directly to fleet terminals, are the cheapest way to buy DEF.
Click here to read more details about The Monitor. The U. Environmental Protection Agency requires vehicle manufacturers to put measures in place to ensure that vehicles cannot run without Diesel Exhaust Fluid DEF.
Before a truck's DEF tank runs empty the driver is given a series of alerts on their dashboard displays much the same way as if they were running low on diesel. If the truck is allowed to run out of DEF the engine's power is reduced, a solid red warning will be displayed and the vehicle speed will be limited to 5 mph until the DEF tank is refilled.
There are a number of safeguards put in place to prevent confusion between diesel and Diesel Exhaust Fluid DEF filler necks. The standard nozzle diameter for DEF is 0. However, a small number of cases have been reported where diesel has been put in the DEF tank.
Diesel is less dense than DEF and will float on top of the DEF in the tank, but even small amounts of diesel can damage your SCR system and we recommend that you contact your dealer immediately and do not drive the vehicle. If DEF is filled into the diesel tank, the engine will stop running almost immediately, and the vehicle will need to be taken to a service center for repair. No, simply run the tank as empty as possible before refilling.
Diesel Exhaust Fluid DEF is a pure chemical, so your bulk storage tank does not need to be cleaned out unless it is contaminated. Environmental Protection Agency's emissions standards for medium- and heavy-duty vehicles, which are among the most stringent in the world.
The majority of truck makers came to the conclusion that the only way to meet these rules without compromising engine performance and fuel efficiency was to use SCR. For more information about the guidelines, see our Emissions Regulation page. Until , its models used a combination of Exhaust Gas Recirculation EGR and emissions credits earned by meeting new legislation ahead of schedule under the banking and trading program.
This meant that Navistar trucks were allowed to emit NOx at levels above those specified in the rules up to a limit of 0.
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