On the base of the product of sulphomethylation of sulphureted alkyl(C₁₅–C₂₁)phenol the new modifications of additives of sulfonate type-thio-bis-hydroxyalkylbenzylsulfonates of calcium were synthesized and characterized. The developed neutral and average alkaline sulphonates have high physico-chemical and functional properties and by indices excel the well-known trade additives C-150 and Hitec 6060М. With the use of the obtained average alkaline additive in the quantity 1.6% the experimental motor oil M-12 BБ was developed that meets all reguirements.