Effects of Various Lubricants and Fuels on Pre-Ignition in a Turbocharged Direct-Injection Spark-Ignition Engine

Abstract

Recently, downsized turbocharged direct-injection engines with high efficiency and power have drawn attention worldwide. However, abnormal combustion can occur when these engines are driven at low speeds with a high load, causing potentially fatal damage to these engines. This phenomenon pre-ignition is known to be caused by lubricant droplets, and the calcium, zinc, and molybdenum components of the lubricant affect the pre-ignition. We performed several experiments to determine the effects of these components, various fuels, and different coolant temperatures on the occurrence of pre-ignition. We also carried out a separate analysis to investigate and compare how each lubricant component affects the frequency and intensity of pre-ignition with each fuel.