Additive Chemistry Effects on the Sequence IID

Three aspects of Sequence IID performance were investigated, including i) lubricant additive impact on crankcase pressure, ii) correlation between crankcase pressure measurements and the Average Rust performance parameter, and iii) correlations among the five component parts of the Average Rust rating. The author found that increased dispersant levels were the main contributor to elevated crankcase pressure measurements; that higher average crankcase pressures correlate with better Average Rust ratings; and that among the component parts of the Average Rust rating, the lifter ball ratings were, consistently, both the lowest and most variable, while the push rod ratings were the highest and most precise.