Deposit forming tendencies of diesel lubricants are normally conducted using full scale engine tests. The use of bench tests to evaluate diesel lubricant deposit forming tendencies and two microanalysis methods, the “Two-Peak” pressurized DSC method developed at National Institute of Standards and Technology and the Penn State Thin Film Microoxidation test, are described in detail. Correlation of the two laboratory bench tests using conventional diesel lubricants and reference fluids are reported. Both methods can be utilized to evaluate diesel lubricants. The advantage of using the “Two-Peak Method” to developing high temperature liquid lubricants is demonstrated.
