Prime Guard DEF Diesel Exhaust Fluid 2.5 GL – Cleaner Performance, Lower Emissions Looking for reliable emissions control for your diesel engine? The Prime Guard DEF Diesel Exhaust Fluid 2.5 GL available at BSD Sale is your go-to solution for meeting EPA standards and improving engine efficiency. This high-quality diesel exhaust fluid is formulated to work seamlessly with Selective Catalytic Reduction (SCR) systems, reducing harmful NOx emissions while maintaining fuel economy and power. It’s non-toxic, easy to use, and safe for all diesel vehicles equipped with SCR.