Here's something most fleet managers don't realize: every time a diesel engine fires, it's creating sulfuric acid inside the crankcase. Sulfur compounds in diesel fuel combust and form sulfur dioxide, which then reacts with moisture to produce corrosive acid. Left unchecked, this acid attacks bearings, cylinder walls, and other critical components.
This is why heavy duty diesel oils contain alkaline reserve additives—measured as Total Base Number (TBN). These compounds neutralize acids throughout the oil's service life. When TBN depletes, acid levels rise and accelerated wear begins. Euro III through Euro V engines face this challenge constantly, especially under heavy loads or extended drain intervals.
Modern formulations like Hexol Supertruck 15W40 include carefully balanced acid neutralizing agents alongside detergent and anti-wear packages to protect heavy duty diesel engines throughout demanding service cycles.
