Oil Conditioning as a Means to Minimize Lubricant Ash Requirements and Extend Oil Drain Interval

A novel approach to condition the lubricant at a fixed station in the oil circuit is explored as a potential means to reduce additive requirements or increase oil drain interval. This study examines the performance of an innovative oil filter which releases no additives into the lubricant, yet enhances the acid control function typically performed by detergent and dispersant additives. The filter chemically conditions the crankcase oil during engine operation by sequestering acidic compounds derived from engine combustion and lubricant degradation. Long duration tests with a heavy-duty diesel engine show that the oil conditioning with the strong base filter reduces lubricant acidity (TAN), improves Total Base Number (TBN) retention, and slows the rate of viscosity increase and oxidation. The results also indicate that there may be a reduction in wear and corrosion. The effectiveness of the filter is demonstrated in tests with two lubricant formulations: an experimental zero-detergent oil and a fully formulated oil. The zero-detergent lubricant contains no detergent additive and is formulated with an ashless antiwear additive. The results indicate that lower lubricant ash levels in combination with this novel oil filter may be used to maintain adequate engine protection, while also reducing ash affects on aftertreatment systems. The strong base filter may also be used to lengthen the oil change intervals of commercially available lubricants.