Fuel-Lubricant Interactions on Stochastic Pre-Ignition Tendency
This work explores the interaction of lubricant and fuel properties on stochastic pre-ignition (SPI). Findings are based statistically significant measurements of cylinder pressure to SPI tendency and magnitude. Specifically, lubricant detergents, lubricant volatility, fuel volatility, fuel chemical composition, fuel-wall impingement, and engine load were varied to study the physical-chemistry effects of fuel-lubricant interactions on SPI tendency. The work illustrates that at low loads, with fuels susceptible to SPI events, lubricant detergent package effects on SPI were non-significant. However, with changes to fuel distillation, fuel-wall impingement or fuel chemistry, lubricant detergent effects could be observed even at reduced loads.