| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for preventing or inhibiting exhaust valve seat recession in a natural gas fueled engine.SOLUTION: A natural gas fueled engine is operated under lubrication with a natural gas engine lubricating oil composition comprising (a) a major amount of an oil of lubricating viscosity and (b) an alkali metal-containing detergent. The natural gas engine lubricating oil composition is substantially free of alkaline earth metal-containing detergents and lithium-containing detergents. |
