Lube oil chemistry influences on autoignition as measured in an ignition quality tester

摘要: Abstract Derived Cetane Numbers (DCNs) of engine lubricating oil/multicomponent 95 Research Octane Number (RON) gasoline surrogate mixtures were measured in an Ignition Quality Tester (IQT). Measurements separately assess the effects calcium- and magnesium-based detergent additive fraction, oil viscosity, degradation, base classification on mixture ignition propensity at conditions with relevance to low speed pre-ignition (LSPI) engines. Testing 0–25% (by mass) blended into a six-component representing unleaded “average” European blend is used determine sensitivity DCN responses variations properties. With one exception, DCNs found increase content. Despite variation calcium magnesium concentrations, for all blends indicate no statistically significant effect either or magnesium. Similarly, neither aging nor peroxide addition yields changes compared untreated oils. However, distinct response lubricant chemical structural At 25% blending surrogate, (RONs) different group oils range from 19.6 (95.7) 42.1 (46.2). The increases increasing API Group (I through IV); however, was decrease V-B surrogate. Using quantitative 1H NMR, trend interpreted be consequence linear vs. branched character paraffinic composition. Taken together, present results that ASTM D6890 test conditions, there attributable reasonable lubricant's content, degree degradation. Instead, isomeric appears most controlling autoignition properties relative those gasolines.