Duramax Diesel Exhaust Fluid. But how much diesel exhaust fluid does the duramax hold? Duramax needs diesel exhaust fluid (def) to meet epa emissions standards.

Enter your engine rpo (lb7, lly, lbz, lmm, lml, l5p) to see detailed fluid capacities and. A supply of clean, fresh diesel exhaust fluid (def) is critical for optimum selective catalyst reduction (scr) efficiency.