LUBRICANTS WITH TITANIUM AND/OR TUNGSTEN AND THEIR USE FOR IMPROVING LOW SPEED PRE-IGNITION

摘要

A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition includes a major amount of a base oil, one or more overbased calcium-containing detergents having a total base number of greater than 225 mg KOH/gram, to provide greater than 900 ppm by weight to less than 2400 ppm by weight of calcium to the lubricating oil composition, and a low speed pre-ignition reducing amount of one or more titanium-containing compounds to provide from 10 ppm to 3000 ppm titanium and/or one or more tungsten-containing compounds to provide from 125 ppm to 3000 ppm tungsten, all based on the total weight of the lubricating composition. The low speed pre-ignition events in the boosted internal combustion engine may be reduced relative to a number of low speed pre-ignition events in the same engine lubricated with the same lubricating oil without the titanium- and/or tungsten-containing additive.

主权项

1. A lubricating oil composition comprising:
greater than 50 wt. % of a base oil of lubricating viscosity,
an amount of one or more overbased calcium-containing detergents having a total base number of greater than 225 mg KOH/g, measured by the method of ASTM D-2896 sufficient to provide greater than 900 ppm by weight to less than 2400 ppm by weight of calcium to the lubricating oil composition, based on a total weight of the lubricating oil composition, anda low speed pre-ignition reducing additive composition comprising an amount of one or more titanium-containing compounds sufficient to provide from 10 ppm to 3000 ppm by weight of titanium to the lubricating oil composition and/or an amount of one or more tungsten-containing compounds sufficient to provide from 125 to 3000 ppm of tungsten to the lubricating oil composition, both based on the total weight of the lubricating oil composition, andwherein said additive composition is effective to reduce low speed pre-ignition events in a boosted internal combustion engine lubricated with the lubricating oil composition relative to a number of low speed pre-ignition events in the same engine lubricated with a same lubricating oil composition without the one or more titanium-containing and/or the one or more tungsten-containing compounds.