Antiknock qualities of clear catalytically reformed naphtha and with tetraethyl lead (TEL) and tetramethyl lead (TML) were studied under various operating conditions of the CFR engine. The operating variables investigated were engine speeds of 600, 900 and 1, 200rpm, ignition timing of 5° to 35° BTDC, air-fuel ratio between 10 and 16, and inlet mixture temperatatures of 50° to 150°C. The lead response was evaluated from increase of incipient knock limited compression ratio.
The effect of TEL or TML varied with engine operating conditions, but generally, lead response in catalytically reformed naphtha was greater at richer mixture and at retarded timing of ignition.
Because the relative effectiveness of TML to TEL varied considerably, depending on operating conditions and lead concentrations, it was difficult to state absolutely which was more effective than the other. It was found that the relationship between the incipient knock limited compression ratio and lead concentration was expressed by the same type of empirical equation as found on octane number and lead concentration.

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Three straight-run light lubricating oil fractions from Kuwait, Venezuela and California crudes were hydrotreated over NiCoMo-Al₂O₃ catalyst by the flow method for the purpose of studying the difference in reactivities of these three fractions and the relationship between the stabilities and the chemical composition of the oils. The reactivities of the fractions under hydrotreating were very different owing to their origins. Results were as follows;
(1) Under the mild conditions decrease in viscosity was proportional to the degree of desulfurization, but under severe conditions (above 80∼90% desulfrization) rapid decrease in viscosity by the cracking etc. was observed. In case of naphthenic oils containing much oxygen-compounds, considerable viscosity decrease was observed in the initial hydrotreating stage. It was supposed that these viscosity decrease was due to the hydrocracking of the oxygen-compounds.
(2) C_A% in ring analysis decreased according to the hydrodesulfurization. In case of Kuwait oils C_P% increased and C_N% did not change, on the contrary C_P% did not change and C_N% increased in California oils. And in Venezuelan oils both C_P and C_N% gradually increased.
(3) Oxidation stability of the hydrotreated oils had good relation with the total sulfur content of the oils. In the range of 0.1∼0.4wt% total sulfur, a maximum oxidation stability was obtained. Hydrotreated Kuwait oils and Venezuelan oils had these "Optimum sulfur range". California oils had inverse relationship, but after the undesirable nitrogen-compounds were eliminated, same "Optimum sulfur range" appeared in the same range.

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