| abstract |
Disclosed herein is lubricating oil composition for providing enhanced piston cleanliness in an internal combustion engine. The lubricating oil composition include (a) from about 50 to about 65 wt. %, based on the total weight of the lubricating oil composition, of a first base oil component having a Kv at 100° C. of about 3.5 to about 4.5 cSt; (b) from about 10 to about 30 wt. %, based on the total weight of the lubricating oil composition, of a second base oil component having a Kv at 100° C. of about 5.5 to about 6.5 cSt; (c) about 1.50 wt. % to about 10 wt. %, based on the total weight of the lubricating oil composition, of at least one Mannich reaction product as disclosed herein; and (d) at least one ashless dispersant other than component (c); wherein the lubricating oil composition has a sulfur content of less than or equal to about 0.30 wt. %, a phosphorus content of less than or equal to about 0.09 wt. %, and a sulfated ash content of less than or equal to about 1.60 wt. % as determined by ASTM D 874, based on the total weight of the lubricating oil composition; and further wherein the lubricating oil composition is a SAE 0W multi-grade lubricating oil composition; with the proviso that when the lubricating oil composition has a sulfated ash content of less than or equal to 0.60 wt. %, based on the total weight the lubricating oil composition, the Mannich reaction product is present in at least about 3.0 wt. %, based on the total weight of the lubricating oil composition. |