A highly effective alkylphenolate additive, V-7140, with an alkali level of 400 mg KOH/g was synthesized in order to improve the performance properties of motor oils. It was shown that the functional and some physicochemical properties of V-7140 additive were superior to a domestic commercial alkylphenolate and its foreign analog ADX410. The excellent functional properties of the additive stemmed from its high alkalinity and colloidal stability in addition to a higher content of active ingredient.