EPA 2010 vehicles equipped with Selective Catalytic Reduction (SCR) technology will use Diesel Exhaust Fluid.   Diesel Exhaust Fluid, also called DEF, is a solution made up of purified water and 32.5 percent automotive-grade urea that is used as a carrying agent for the ammonia needed to reduce nitrogen oxide (NOx) emissions from vehicles into nitrogen, water and carbon dioxide (CO2).

 A typical North American Fleet Sleeper Tractor will likely fill its Diesel Exhaust Fluid tank once every 10 days….or top off every 2 or 3 days1