A lubricating oil composition containing sulfurized calcium alkylphenolate detergent dispersant of superior resistance to oxidation prepared by (1) reacting at a temperature between 200.degree. and 425.degree.F. alkylphenol with a first addition of calcium alkoxyalkoxide to form a calcium alkylphenolate containing first reaction mixture utilizing between about 45 and 90 wt. % of the stoichiometric amount required to convert the alkylphenol to calcium alkylphenolate, (2) contacting the calcium alkylphenolate first reaction mixture with sulfur at a temperature between about 440.degree. and 460.degree.F. in the presence of between about 13 and 20 wt. % of a hydrocarbon lubricating oil based on step 2 second reaction mixture, and (3) contacting the second reaction mixture with a second addition of calcium alkoxyalkoxide at a temperature between about 350.degree. and 425.degree.F., said first and second addition totalling between about 100 and 120% of the stoichiometric amount of calcium alkoxyalkoxide to form said calcium alkylphenolate, said steps 1 and 3 being advantageously conducted while blowing their respective reaction mixtures with inert gas, step 2 being conducted while sequentially blowing step 2 reaction mixture with inert gas, carbon dioxide and inert gas.