Abstract: A two-stroke or four-stroke marine engine lubricating oil composition comprising an oil of lubricating viscosity in a major amount and (A) additives, in respective minor amounts; and (B) an olefin copolymer viscosity modifier. Preferably, brightstock is completely or substantially absent from the composition.

Abstract: A two-stroke or four-stroke marine engine lubricating oil composition comprising an oil of lubricating viscosity in a major amount and (A) additives in respective minor amounts; and (B) a polymethacrylate viscosity modifier. Preferably, brightstock is completely or substantially absent from the composition.

Abstract: A two-stroke or four-stroke marine engine lubricating oil composition comprising an oil of lubricating viscosity in a major amount and (A) additives, in respective minor amounts; and (B) a viscosity modifier in the form of a polymer comprising a core and a plurality of polymeric arms extending therefrom. Preferably, brightstock is completely or substantially absent from the composition.

Abstract: An aviation piston engine lubricant having no metal containing additive is provided. The lubricant contains (a) a base oil consisting essentially of a mixture of (i) at least about 50 wt % based on the total weight of the lubricant of one or more mineral oils having a viscosity in the range of about 5 cSt to about 25 cSt at 100° C. and (ii) about 15 to about 40 wt % based on the total weight of the lubricant of a polyalpha olefin fluid having a viscosity in the range of about 4 cSt to about 40 cSt at 100° C.; (b) at least about 3 wt % based on the total weight of the lubricant of an ashless polyisobutylene succinic anhydride/polyamine (PIBSA/PAM) dispersant; and (c) an effective amount of one or more ashless additives selected from the group consisting of antiwear agents, extreme pressure agents, metal passivators, and antioxidants.