Diesel Exhaust Fluid

Diesel Exhaust Fluid (DEF) is one of the key elements of the Selective Catalytic Reduction (SCR) process used by most medium and heavy-duty engine builders to meet EPA 2010 regulations. DEF is a nontoxic solution of 67.5% purified water and 32.5% ultra pure automotive grade urea. DEF is not a fuel or fuel additive. Instead, when injected into the exhaust stream and passed over a catalyst, DEF helps convert NOx into nitrogen gas and water vapor – two harmless and natural components of the air we breathe. DEF is stable, colorless and odorless, and meets ISO Standards 22241 for purity and composition. Making sure you do not run out of DEF in a SCR equipped truck is simple – watch the Diesel Exhaust Fluid (DEF) gauge, which is part of the diesel fuel gauge, for when it is time to refill. DEF is stored in a dedicated tank next to the fuel tank on the driver’s side. The tanks range in size from 6 to 23 gallons depending on the truck’s application. The DEF tank fill opening is designed to accommodate a DEF fill nozzle to ensure only DEF is put into the tank. A diesel fuel nozzle will not fit into the DEF tank opening. To order, contact your InterState Oil Company customer service representative. For further information, please contact us.