Abstract
This paper investigates the friction and wear properties of the fresh and soot-contaminated API CF-4 and CI-4 diesel engine oil using the SRV4 tribometer. It was found that the comprehensive wear properties of CI-4 oil was better than those of the CF-4 oil. Tests of the fresh and contaminated CF-4 oil in combination with two types of rings of different surface treatment showed discriminations, and these discriminations also reflected on the CF-4 oil tests with test rings of different surface coatings.
