running-in oil

例句：

1. 1. The engine needs regular running-in to keep it in good condition.
   发动机需要定期运行以保持良好状态。
2. 2. The car's engine is running-in oil now.
   汽车的引擎现在正在运行润滑油。
3. 3. The mechanic checked the engine and replaced the running-in oil.
   机械师检查了引擎，并更换了润滑油。