A lubricating composition containing (a). at least 3 weight percent of an
overbased sulphonate detergent with a metal ratio of 12.5:1 to 40:1; (b).
at least 1.5 weight percent of a sulphur containing phenate detergent
with a metal ratio of not more than 2.5; and (c). an oil of lubricating
viscosity, wherein the sulphur containing phenate contains oligomers of
hydrocarbyl phenol with at least 50 wt % of said oligomers in the form of
the tetramer or higher oligomers. The composition is suitable for
internal combustion engines, particularly marine diesel applications to
provide improved cleanliness decreased cylinder wear and reduced
deposits.