In order to study the impact of trace elements on the engine oil performance,the elemental content of engine oil was analyzed by atomic emission spectrometry.The influence of trace element content on the friction and wear properties of engine oil was investigated by combining SRV friction and wear test,and the influence of trace element content on the fuel economy was also investigated by combining the vehicle fuel consumption test.It is concluded that the Ca element has a positive correlation with the friction and wear properties of the engine oil and the S element has a positive correlation with the fuel economy of the engine oil.