PURPOSE: To provide an alkenyl succinimide useful as a dispersant additives to a lubricating oil compsn.

CONSTITUTION: This deriv. has an alkenyl group which has a number average mol.wt. (Mn) in a range of 700 to 5000 and is substantially derived from the atactic propylene oligomer substantially of formula I ((n) is 15 to 120) and a molar ratio of a succinic acid part : atactic propylene oligomer in a range of 1:1 to 1.5:1. The succinimide is derived from the 1 to 50C amine expressed by formula II ((m) is 1 to 9: (p) is 2 to 4). In addition, the processing for producing the succinimide derivatives and the lubricant compsn. contg. these derivatives.