Abstract
The manufacture of high grade gasolines and lubricating oils force the fuels oils to be lower in grade, and such low grade fuel oils are used for low speed diesel engines to save expenditure in recent trend.The author discusses the effects of low grade fuels for motoring engines from the view point of the nature of oils such as specific gravity, viscosity, sulfur contents, carbon residue, ash and moisture.On mecha-nical counter-measure for the troubles caused by the low grade fuels, he describes heating of fuel, installation of purifier, use of combustion catalyser and selection of lubricating oil.He introduced the gas diesel engine using natural gas in Niigata.
