knock rating的用法和樣例：
例句
- Another problem is that existing petrol engines cannot take advantage of the much higher octane rating.
另外一個問題是現有的汽油引擎無法利用更高辛烷值的優勢。 - However, if it knocks heavily under most driving conditions while you are using fuel with the recommended octane rating, see your authorized dealer to prevent any engine damage.
可是，在使用推薦的辛烷值燃油時，要是在大部分行駛條件下爆震嚴重，請找你的福特授權經銷商，避免任何對於發動機的損傷。
