摘要 |
This invention relates to a method of reducing intake valve deposits in a direct injection engine, the method comprising lubricating the engine with a lubricating oil composition comprising a base oil mixture, the base oil mixture comprising (i) a Group III, a Group IV oil, or a mixture thereof, in combination with (ii) a synthetic ester oil, the weight ratio of (i) to (ii) being from about 0.2:1 to about 6:1.
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