Doc's Diesel 15W-40 Full Synthetic Heavy-Duty Diesel Oil 55 Gallon Drum 5.9L cummins The XL size is slightly

The XL size is slightly lighter in color than the other sizes

D6128+D10W30

While engine oil does a great job protecting your engine

1% Efficiency Rating - Efficiency SAE J1985 3rd-Party Test Results

Controls moisture by removing water from fuel to prevent corrosion and microbial growth

Doc's Diesel 15W-40 Full Synthetic Heavy-Duty Diesel Oil 55 Gallon Drum 5.9L cummins The XL size is slightlyDoc's Diesel Engine Oil: Doc's Diesel 15W 40 Full Synthetic Heavy Duty Diesel Oil is specially engineered for todays hard working diesel engines whether you're running a new emissions compliant rig or keeping an older workhorse in the game. Engineered for excellent wear protection, our oil thrives in severe operating conditions, ensuring that your engine stays protected under the toughest circumstances. With strong oxidation and viscosity control, it