Lubricating oil composition for outboard engines
AssigneeInfineum International Limited
InventorsRolfe J. Hartley, Salvatore Rea, Malcolm Waddoups
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Abstract
The lubricating compositions of the present invention are designed for use in a four stroke outboard marine engine and contain an oil of lubricating viscosity, an ashless dispersant, a metal detergent, a rust inhibitor, a relatively high amount of ZDDP, and an amount of a molybdenum compound sufficient to provide the composition with 15-1,000 ppm by mass of molybdenum. An amount of about 15 ppm to 1,000 ppm by mass of molybdenum from a molybdenum compound has been found to be effective as an antiwear agent in combination with the high levels of ZDDP.
Claims14
A lubricating oil composition suitable for use in a four stroke outboard marine engine which comprises an oil of lubricating viscosity containing an admixture of
- (a) 1-3.25 wt % of an ashless dispersant;
- (b) a metal detergent;
- (c) an oil soluble molybdenum compound in an amount sufficient to provide 15-1,000 ppm molybdenum in the composition;
- (d) a zinc dialkyl dithiophosphate in an amount sufficient to provide at least 1,200 ppm phosphorus in the composition;
- (e) a rust inhibitor;
- and
- (f) optionally, a viscosity modifier, said composition having a NOACK volatility less than 15%.
Dependencies are inferred from the claim text.