This paper describes a study of the effects of oil composition on visible smoke, engine cleanliness, and piston anti-seizure performance. Two laboratory tests, termed the DSC (Differential Scanning Calorimeter) method, and the HTT (Hot Tube Test) are investigated as screening tests for two-cycle engine oils.
Two types of oil were developed to comply with stringent Japanese oil requirements. Firstly, smokeless type oils formulated, with high concentrations of polybutenes were introduced to greatly reduce visible smoke from two-cycle engines of high specific output. Secondly, low-friction oils containing ester type synthetic base stocks were developed to achieve higher engine output in racing applications.