| abstract |
A lubricating composition comprising an oil of lubricating viscosity; an amine salt of a phosphorus acid ester; a thiadiazole copper corrosion inhibitor; an overbased metal detergent; a boron compound; and at least one friction modifier provides good lubrication of a mechanical device such as a farm tractor, even though such composition is substantially free from zinc dialkyldithiophosphate. |