汽油的牌号表示了汽油辛烷值的高低。有些摩托车用的合适牌号的汽油很难买到,或手中有低牌号汽油无法用在用高牌号油的发动机上。虽然汽油牌号差几号对发动机 Gasoline grades indicate the level of octane number of gasoline. Some motorcycles with a suitable grade of gasoline are difficult to buy, or the hands of low grade gasoline can not be used in the engine with a high grade of oil. Although the difference between the number of gasoline on the engine