The last eight years has seen major changes in the formulation of lubricating oils for virtually all reciprocating engine applications. This is due primarily to two factors: increased demands of the engines themselves and availability of new lubricating oil additive components. In the United States, today's cars require crankcase oils of superior deposit and wear control because of the trend toward longer oil drains and the widespread use of positive crankcase ventilation systems. The new additive components that have made the formulation of improved oils possible are highly overbased sulfonates and phosphonates, high base phenates, and succinimide ashless dispersants. The overbased metal salt detergents represent evolutionary improvements and are used in a wide variety of oil formulations as detergents and acid netralizers to reduce deposits and prevent corrosive wear and rusting. The succinimides are considered to be one of the most important developments in the history of lubricating oil additives. Their remarkable dispersant properties under both low and high temperature conditions permit lubricant performance levels in passenger cars, high-speed diesel engines, railroad diesel locomotives, and natural gas engines that were hitherto impossible.

Over the past 30 years, oil companies and additive suppliers have spent millions of dollars on research and development of lubricating oil additives. In spite of this, the number of major additive components by E. J. McLAUGHLIN, Vice-President, Chevron Chemical Company General Manager, Oronite Additives Division, San Francisco, California, U.S.A and F. A. STUART, Manager, Lubricants Division, Chevron Research Company, Richmond, California, U.S.A.

Rsum Pendant les huit dernires annes, des changements importants ont eu lieu dans les formulations d'huiles lubrifiantes pour presque toutes les applications de moteurs piston. Ceci est attribuable principalement deux facteurs: les exigences accrues des moteurs mmes et la disponibilit de nouveaux constituants additifs pour les huiles lubrifiantes. Aux Etats-Unis, les voitures actuelles demandent des huiles de carter ayant des proprits superieures en ce qui concerne l'inhibition des dpts et de l'usure, en raison de la tendance prolonger les priodes de vidange di'huile ainsi que de l'usage rpandu des systems de ventilation positive du carter. Les nouveaux constituants additifs qui ont permis de formuler des huiles perfectionnes sont des sulfonates et phosphonates fort excs de base, des phnates hautement basiques et des dispersants succinimidiques sans cendres. Les dtergents de sels metalliques excs de base reprsentent des perfectionnements volutionnaires est sont employs dans toutes sortes d'huiles comme dtergents et neutralisants d'acide pour rduire les dpts et empcher l'usure par corrosion et la rouille. On considre les succinimides comme un des d

This content is only available via PDF.
You can access this article if you purchase or spend a download.