Oil analysis consists of various tests performed on each sample of oil returned to the laboratory. The results of these analyses, when compared, reveal lubricant condition, contamination levels, and wear rates of oil-lubricated components. The results of an oil analysis provide information about several characteristics of the oil. An understanding of these results helps get the most life out of the oil.
Viscosity is the most important single property of lube oil.
In used oil analysis, the test is performed to determine whether the oil has thickened or thinned excessively. Abnormal results indicate that some operational or maintenance defect exists that should be corrected. Fuel Dilution is the most common cause of oil thinning in diesel engines. The results of fuel dilution are reported as percentage by weight or volume. Water can contaminate diesel engine crankcases as a product of combustion or due to coolant leaks.