the invention comprises an ashless additive of the formula : ## str1 ## in which z is oxygen or nitrogen . r is alkyl or alkenyl of more than 40 carbon atoms , inclusive , r &# 39 ; is -- 2 when z is nitrogen or m h when z is oxygen , r &# 34 ; is -- r &# 34 ;&# 39 ; nh or -- m h or mixtures thereof , r &# 34 ;&# 39 ; is an alkylene group of 2 - 3 carbon atoms , m is 5 to 20 ; or the corresponding boric acid esters ; or the corresponding boric acid ester of the reaction product of polyalkenylsuccinic anhydride and a n , n , n &# 39 ;- tris alkylalkylenediamine ; for use in lubricating oils , to methods for preparing the additives , and to lubricating compositions containing the additives .