Acid neutralization is one of the key performance indicators for engine oil. The ability to neutralize acids while maintaining the alkaline reserves is measured by TBN (total base number) and TAN (total acid number) through used oil analysis. As the TAN rises throughout the oil drain interval, the TBN depletes, which creates a cross-over point where the TAN and TBN become the same numerical value.
Castrol Hypuron Advanced Formula 10W-30 diesel engine oil prolongs reaching the cross-over point versus other leading competitive 10W-30 engine oils, which enables longer drain intervals and better acid formation protection. The TBN/TAN cross-over point is one of several measurements needed to correctly determine the optimized drain interval for your fleet.
Castrol Hypuron Advanced Formula 10W-30 delivers outstanding protection from acids, wear, oxidation and soot, which enables “extreme” engine oil drain intervals up to 70,000 miles.*