| abstract |
A lubricating oil composition and method of operating a boosted internal combustion engine. The lubricating oil composition includes greater than 50 wt.% of a base oil, one or more overbased calcium-containing detergents having a TBN greater than 225 mg KOH/g and one or more magnesium-containing detergents. A total amount of calcium from the one or more overbased calcium-containing detergents is from 900 ppm to less than 2400 ppm by weight, and a total amount of magnesium from the one or more magnesium-containing detergents is from 50 ppm to 500 ppm by weight, both based on a total weight of the lubricating oil composition. The lubricating oil composition and the method of using it are effective to reduce low speed pre-ignition events in a boosted internal combustion engine lubricated with the lubricating oil composition. |