Onodera, K., Kato, T., Ogano, S., Fujimoto, K. et al., "Engine Oil Formulation Technology to Prevent Pre-ignition in Turbocharged Direct Injection Spark Ignition Engines," SAE Technical Paper 2015-01-2027, 2015, doi:10.4271/2015-01-2027.
Engine oil formulation is known to affect low speed pre-ignition (LSPI), which creates technical restrictions on downsized turbocharged engines. Calcium, which is used to ensure detergency and anti-rust performance, is reported to increase LSPI events. Therefore, new formulation technologies are needed to satisfy both LSPI prevention performance and other conventional performance areas.The authors focused on two approaches: enhancement of LSPI prevention performance by adding a booster component and substitution of calcium for a less reactive component to balance performance areas including LSPI prevention. We have verified the effectiveness of these approaches by increasing the dosage of molybdenum used as a friction modifier as well as replacing calcium detergent with a magnesium detergent. These formulation strategies can be applicable for future ILSAC GF-6 engine oil, where a specification for LSPI prevention performance is expected to be implemented.