Abstract
Abnormal combustion phenomena especially referred as low speed pre-ignition (LSPI) is so destructive that the torque and fuel economy of turbo charged direct injection gasoline engine are restricted. Recent technical papers report that the additives in engine oil are related to the occurrence of LSPI events. In order to verify the results of reports and seek for a kind of oil which is capable for running at IMEP 2.4MPa without LSPI, 8 kinds of oil blended with the combination of 3 additives (Ca, Mg, Mo) were tested on a 2.0L turbo charged direct injection engine. Different to other previous researches, the test conditions were set at various kinds of engine load, engine speed and EGR ratio, in particular, up to IMEP 2.4MPa was conducted for the evaluations. Thereby, the influences of engine load, engine speed and EGR ratio were also evaluated.
