Cobra Performance Lubricants & Specialty Fluids
Home |  SDS | Français
Cobra Performance Lubricants & Specialty Fluids

Diesel Exhaust Fluid

What is DEF?
What is an SCR?
Infotech Sheet
Product Categories

Frequently Asked Questions?

Q. Why do I need DEF?
A. DEF is the fluid that is dosed by the SCR in order to convert dangerous Nox emissions into harmless water vapor and Nitrogen. Without DEF your SCR will not be able to meet EPA standards of 90 percent reduction.

Q. If I run out of DEF while driving what happens?
A. A driver should not run out of DEF as there are indicators on all vehicles to provide warnings that they are running low. If for some reason you do run out of DEF while driving the power to the vehicles engine will decrease significantly. Vehicle speed will be limited to 5 mph until the DEF supply is replenished. Drivers are always encouraged to carry at least one container of DEF in their vehicle to avoid this happening during runs.

Q. How much DEF will my vehicle consume?
A. DEF is measured as a ratio to Diesel fuel use, generally a vehicle doses between 2-3%. Recent feedback from the field suggests that the dosing rate originally predicted is actually more like 2 – 2.5%.

Q. How much would you pay for DEF?
A. The price you will pay for DEF depends on many factors, where you are located, where the supply is coming from, volume and volatility of the market. Manufacturers and suppliers work very closely to ensure pricing for DEF is aligned in the market and cost competitive for the driver.

Q. What is the shelf life for DEF?
A. If kept at temperatures between -11 degrees F and 86 degrees F, and out of direct sunlight, there is a 2 year shelf life. Bulk dispensers are climate controlled and thus able to maintain optimal temperatures.

Q. What were the standards set forth by the Clean Air Act in 2010?
A. There are different standards that have been set by different Environmental Protection Agencies around the world. In North America emissions standards were set at Nox limits of 0.20 g/bhp-hr in January of 2010. DEF coupled with SCR is the solution that was formulated in order for Diesel engines to meet these standards.

Q. How important is the purity of the DEF?
A. The single most important standard for DEF is its purity. For fleet the DEF solution is 32.5 percent Urea to De-Ionized water, non-pure water is the biggest threat to your catalyst and can cause costly repairs. This standard has been set and enforced through API certification in order to ensure the exact formula is reached for every single batch. Every mixture of DEF is analyzed to ascertain that the proper levels are met; a miniscule amount of contaminant can have serious repercussions. It is extremely important that the DEF you use be API certified and meets ISO 22241 standards. Irving DEF meets all the requirements of both API and ISO 22241.

Q. Is there a danger of putting DEF in the wrong tank?
A. Yes it is possible to put DEF in the wrong holding tank but many safe guards have been put in place to mitigate this risk. The Diesel nozzle will never fit inside the opening for the DEF tank as it is a much larger nozzle in diameter to the DEF tank opening. The standard nozzle for DEF is 0.75 inches or 19mm in diameter and for Diesel fuel this is 0.87 inches or 22mm. The caps are also color coded to help drivers identify specific tanks. For DEF the cap is blue and has DEF clearly marked on the outside with the ISO standard number. There have been instances where Diesel fuel has been pumped into the DEF tank although this fuel will float to the top the risk of damage to the tank is still there and you should contact the manufacturer immediately. Do not drive the vehicle until you have gotten in touch with your manufacturer.

Q. If I have one brand of DEF and switch to another is this OK?
A. Due to the standardization of DEF and the stringent quality controls you are able to add DEF to your tanks as long as the DEF you are purchasing is API certified and meets ISO 22241 standards. Irving DEF meets all the requirements of both API and ISO 22241.

Q. Is DEF toxic, how should I deal with a spill?
A. DEF is non-toxic and a non pollutant. If you spill a small quantity of DEF you can dilute with water and dispose of in a garden, green area etc. DEF as it dries turns to Crystals, these are harmless and can just be swept away. If a large amount of DEF is spilled the area must be contained, diluted with water and then removed and disposed of as per your areas protocol. DEF is corrosive to some metals such as steel, aluminum, zinc and copper due to oxidation. The containers DEF is stored in are specifically utilized to mitigate any corrosion or contamination.

Q. How do I know that the DEF I purchase will work?
A. All certified DEF will have an API certified marker and display the certification of the German Institute of Standardization DIN70700, the International Organization for Standardization ISO 22241-1 and meet AUS – 32 specifications. This will ensure the proper concentration (32.5%) of urea.

Q. Does DEF freeze and if so, is it still good to use?
A. Yes DEF does freeze at 11 de F or -11 deg C. Frozen DEF will not stop a vehicle from starting and part of the SCR has a heating element that quickly thaws the DEF in its tank. DEF can be frozen and thawed with no repercussions to operating or its effectiveness.