DEF: Diesel Exhaust Fluid

At Brown & Son’s Fuel Company, we are proud to be an official distributor for DEFendal Diesel Exhaust Fluid.  We carry the following sizes for DEF distribution:

What is DEF?

Diesel Exhaust Fluid (DEF) is a new product required by many heavy-duty trucks, pickups, SUVs and vans delivered after January 2010. DEF is used to destroy harmful emissions in the exhaust and meet the EPA’s latest strict environmental standards.

DEF is non hazardous and consists of 67.5% de-ionized water and 32.5% urea, and is used in combination with Selective Catalytic Reduction (SCR) technology. It is sprayed into the exhaust and combines with a catalyst to break down NOx (a harmful pollutant) into nitrogen and water.

In January 2010 emissions legislation came into force which requires diesel vehicles to significantly reduce harmful emissions of NOx and particulate matter. A good way to meet these standards is to use SCR and DEF. The trucking industry has been split in two by this latest piece of rule making and manufacturers are pursuing two technology pathways. Daimler, PACCAR, Volvo, Mack, Isuzu, Hino, Ford, GM and others are using SCR, while Navistar has decided to go it alone and use an extension of its 2007 MaxxForce EGR technology.

FAQs about DEF: Diesel Exhaust Fluid

Why is Diesel Exhaust Fluid needed?
The EPA has mandated that all on-road diesel vehicles manufactured in 2010 must be equipped with systems to reduce NOx emissions. To read more about NOx emission standards, click here.

What is Diesel Exhaust Fluid?
32.5% high purity automotive grade urea and 67.5% DI water. Urea is a common agricultural fertilizer that is usually manufactured from natural gas. To read more about KleenDEF™ Diesel Exhaust Fluid, click here.

Can I mix this fluid myself?
No, it is not advised. The process in which this fluid is mixed is very specific. The on-board system knows if the fluid is out of specification or if there is contamination.

Do I change this fluid out, and how much do I need?
Since this fluid is consumed at a rate of 2-4% of diesel fuel, this fluid is refilled rather than replaced with other engine products such as antifreeze and engine oil. Tanks on board vary in size from 16-50 gallons in the largest trucks, with the average size around 20 gallons. The tank must have fluid in it to operate.

How will a driver know when they are low on Diesel Exhaust Fluid?
Similar to fuel tank indicators, DEF indicators will exist on all of these vehicles. There are simple warning indicators located on the dash board for the drivers indicating the level of the fluid.

What happens if Diesel Exhaust Fluid gets too hot or too cold?
When DEF gets too cold there is no harm whatsoever to the shelf life of the fluid, however it will begin to freeze at 11ºF. Trucks will start, and the tank will be heated until the solution starts to flow, and the driver is on his way. Storage for long periods at high temperatures can reduce the shelf life of the fluid. Temporary exposure to hot temperatures and sunlight do not have harmful effect on the fluid.

I can see a driver trying to put diesel fuel in his DEF tank since they are so close together, can this be avoided?
To avoid this, the industry standard for onboard DEF dispensing openings is smaller than that for diesel tanks. The nozzles at fuel islands for diesel fuel will not fit the onboard DEF tanks.

How is DEF quality defined and guaranteed?
DEF is defined by AUS-32 specifications, which require the fluid to meet the DIN 70070 August 2005 standard, DIN V 70071 June 2005, and the ISO 22141-1 2006 standard. The API has in place a quality certification program that ensures that North American suppliers of DEF will meet these standards at the pump, and across the nationwide supply chain. KleenDEF™ Diesel Exhaust Fluid is formally API approved.

How much will I need and how big is my tank?
The average on-road tank size is 20 gallons, however they do vary depending on the application. They typically range from 6 to 30 gallons.

Is contamination really a concern?
Yes, contamination can plug the input of DEF into the catalyst chamber. SCR unit performance will be compromised and can eventually fail leading to expensive repair costs.

To learn more about DEF, please visit: