"Add Oil" is the literal English translation of the Chinese phrase "Jiāyóu" (Cantonese "Ga Yau"), which is used to express encouragement, (excite), or support to others. It's used in sporting events (encourage) a friend, and in many other conversations!
"Add Oil" has now been added the Oxford English Dictionary. The Oxford English Dictionary entry describes the phrase as "chiefly Hong Kong English", and notes its (early) appearance in a book published back in 1964.
Some people believe that the phrase (invent) at the Macau Grand Prix (澳门汽车大奖赛) during the 1960s, where the crowd would shout at the pit teams (加油团队) to "Add Oil!" to the racing cars. The meaning of the Chinese characters is to add (jiā) oil (yóu), which implies (add) oil/fuel to an engine to fire up.
In places such as Hong Kong, where a mixture of Chinese and English is (common) used among friends, the English phrase often replaces the Chinese characters, and this is the reason the phrase has been added to the dictionary.
The latest addition to Oxford English Dictionary is by no means a stand-alone. Other Chinese phrases that (enter) everyday English include "long time no see" and "no can do".
