It ACTS more as a 10 grade oil at startup.

在冷启动时它相当于10粘度级机油。

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This is unlike the counterpart mineral oil based on a 10 grade oil.

它不像同样标号的矿物油基于10粘度级基础油。

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Note that a straight 10 grade oil is also too thick for your engine at startup.

请注意纯10 粘度级的机油在你启动时都是过厚（粘）的。

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Both involve heating organic materials in a vacuum until they break down into carbon and vapors that can be condensed into a low-grade fuel oil.

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Much of Venezuelan oil is also heavy oil, which is a lower grade.

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Recent bidding rounds have attracted lucrative offers from scores of foreign firms, not surprising since Libyan oil tends to be high-grade and cheap to produce, and only a quarter of the country has been explored.

ECONOMIST: Libya