Abstract: This invention relates to processes and compositions for stabilizing distillate fuel oil which comprises adding to the distillate fuel oil an effective stabilizing amount of a mixture of (a) a phosphite compound having the formula ##STR1## wherein R, R' and R" are the same or different and are alkyl, aryl, alkaryl or aralkyl groups and these groups may contain oxygen and/or nitrogen, or R and R' may be hydrogen and (b) an effective stabilizing amount of: an organic compound containing a tertiary amine having the formula T.sub.3 N, wherein the three T groups are the same or different and are alkyl, cycloalkyl, arly, alkyaryl, or aralkyl such that these groups may contain oxygens or additional nitrogens and each T group has from 1 to about 20 carbon atoms; or the reaction product of tallow amine and epichlorohydrin. The weight ratio of (a):(b) is from about 1:50 to about 100:1.