Advances in Hydraulic Oil Additive Technology

The status of hydraulic oil additive technology is briefly reviewed with emphasis on recent advances. New test methods now being introduced into the industry are examined and results of comparative testing presented. A comprehensive analysis and performance comparison is made of the two main technologies: ashless and zinc dithiophosphate. It is shown that the ashless (S, P) approach is superior to the zinc-based one in most performance areas and offers industry the option for a truly multipurpose hydraulic oil.