Diesel Exhaust Fluid (DEF) is an Aqueous Urea Solution formulated for your SCR system. Diesel Exhaust Fluid (DEF) DEF is a urea-based chemical reactant designed specifically for use in SCR systems to reduce NOx emissions. All of our DEF meets accepted international standards for purity and composition, including ISO22241, and API® (American Petroleum Institute) certification. Calculating DEF Usage DEF usage varies based upon vehicle operation, duty cycle, environmental conditions, and ratings. For most on-highway vehicles, DEF consumption is approximately 2% of diesel fuel consumption.

To calculate your DEF consumption, use the following equation: Annual Consumption = (Annual mileage / MPG) * 2% * Number of Vehicles Storage DEF should be stored in a cool, dry, well-ventilated area, out of direct sunlight. While the optimum storage temperature is up to 77° F (25° C), temporary exposure to higher temperatures has little to no impact on the quality of DEF. DEF should be kept from freezing. Maintain System per your Engine Manufacturer’s Recommendations Improper use of DEF in the engine and after treatment systems is highly likely to cause significant damage. Take care to avoid cross contamination of DEF into the diesel fuel tank; likewise, avoid dispensing of diesel fuel into the DEF tank.