Abstract: Compositions comprising a hydrocarbonaceous middle distillate fuel and a minor wear-inhibiting amount of a combination of (i) at least one fuel-soluble aryl phosphate of the formula(RO).sub.3 POwherein each R is, independently, phenyl or an alkyl-substituted phenyl group; and (ii) at least one fuel-soluble aryl polyphosphate of the formula ##STR1## wherein each R is, independently, phenyl or an alkyl-substituted phenyl group, Ar is m-phenylene or an alkyl-substituted m-phenylene group, and n is from 1 to 4. The combination contains from 2 to 30% by weight of component (i). These compositions are made by (a) reacting about 1.9 to about 2.1 equivalents of phenol or alkyl-substituted phenol with one equivalent of phosphoryl trihalide, and (b) reacting the intermediate product formed in (a) with from about 0.9 to about 1.1 equivalents of resorcinol or alkyl-substituted resorcinol per equivalent of phosphoryl trihalide employed in (a). Alternatively, the compositions are made by (a) reacting about 0.9 to about 1.

Abstract: When a phenol having substituents in at least the 2- and 4-positions but having a hydrogen atom in the 6-position, or a phenol having substituents in at least the 2- and 6-positions but having a hydrogen atom in the 4-position is reacted with formaldehyde and 1,3-propanediamine, a unique insertion-condensation reaction occurs whereby the product is a hexahydropyrimidine derivative which may be represented by the general formula ##STR1## wherein R.sub.1 is (i) a 2-hydroxybenzyl group having an inert substituent (preferably a hydrocarbyl substituent) in at least the 3- and 5-positions or (ii) a 4-hydroxybenzyl group having an inert substituent (preferably a hydrocarbyl substituent) in at least the 3- and 5-positions; and R.sub.

Abstract: Liquid mixtures of alkyl phenols composed of from 1 to 8 wt % of 2-tert-butylphenol; from 4 to 12 wt % of 2,6-di-tert-butylphenol; from 4 to 12 wt % of 2-tert-butyl-4-n-butylphenol; from 4 to 12 wt % of 2,4,6-tri-tert-butylphenol; and from 65 to 89 wt % of 2,6-di-tert-butyl-4-n-butylphenol having a balance of properties rendering them ideally suited for use as stabilizers for middle distillate fuels. Such mixtures can be readily produced by an aldehyde-catalytzed alkylation procedure using n-butanol, an appropriate mixture of tertiary butylated phenols, and a strong base (e.g., NaOH, KOH, etc.).

Abstract: Liquid mixtures of alkyl phenols composed of from 1 to 8 wt % 2-tert-butylphenol; from 4 to 12 wt % of 2,6-di-tert-butylphenol; from 4 to 12 wt % of 2-tri-tert-butylphenol; and from 65 to 80 wt % of 2,6-di-tert-butyl-4-n-butylphenol have a balance of properties rendering them ideally suited for use as stabilizers for middle distillate fuels. Such mixtures can be readily produced by an aldehyde-catalyzed alkylation procedure using n-butanol, an appropriate mixture of tertiary butylated phenols, and a strong base (e.g., NaOH, KOH, etc.).

Abstract: Coking in and around the injector nozzles of indirect injection compression ignition engines is reduced by means of distillate fuel with which has been blended suitable concentration of:(a) organic nitrate ignition accelerator, and(b) the condensation product of a phenol, preferably a high molecular weight alkylphenol, and aldehyde and an amine having a H-N< group.Also described are additive mixtures of (a) and (b) for use in distillate fuels in amounts sufficient to reduce the coking tendencies of such fuels when used in the operation of indirect injection compression ignition engines.

Abstract: Coking in and around the injector nozzles of indirect injection compression ignition engines is reduced by means of distillate fuel with which has been blended suitable concentrations of:(a) hydrocarbyl-substituted succinimide,(b) hydrocarbyl amine having from 3 to 60 carbons and from 1 to 10 nitrogens, and(c) N,N'-disalicylidene-1,2-diaminopropane.Also described are additive mixtures of (a), (b) and (c) for use in distillate fuels in amounts sufficient to reduce the coking tendencies of such fuels when used in the operation of indirect injection compression ignition engines.

Abstract: Coking in and around the injector nozzle of indirect injection compression ignition engines is reduced by means of distillate fuel with which has been blended suitable concentrations of(a) organic nitrate ignition accelerator,(b) copolymer of an alpha-olefin having from 8 to 30 carbon and an N-substituted maleimide wherein the N-substituents are organic radicals having from 3 to 60 carbons and from 1 to 5 amine nitrogens, said copolymer having from 4 to 20 repeating olefin-maleimide units, and(c) hydrocarbyl amine having from 3 to 60 carbons and from 1 to 10 nitrogens.

Abstract: Coking in and around the injector nozzles of indirect injection compression ignition engines is reduced by means of distillate fuel with which has been blended suitable concentrations of:(a) organic nitrate ignition accelerator,(b) hydrocarbyl amine having from 3 to 60 carbons and from 1 to 10 nitrogens, and(c) N,N'-disalicylidene-1,2-diaminopropane.Also described are additive mixtures of (a), (b), and (c) for use in distillate fuels in amounts sufficient to reduce the coking tendencies of such fuels when used in the operation of indirect injection compression ignition engines.

Abstract: Coking in and around the injector nozzles of indirect injection compression ignition engines is reduced by means of distillate fuel with which has been blended suitable concentrations of:(a) organic nitrate ignition accelerator, and(b) hydrocarbyl-substituted succinimide.Also described are additive mixtures of (a) and (b) for use in distillate fuels in amounts sufficient to reduce the coking tendencies of such fuels when used in the operation of indirect injection compression ignition engines.