as the other's have said it means "add oil", but oil as in petroleum i.e. gasoline/gas that goes in a gas/petrol tank, equivalent English expressions in BrE and AmE would be to "put your foot down on the accelerator" and to "step on the gas"
The expression is from the 60s or 70s, but it is extremely common. I hear my Chinese friend saying this and I say it myself almost every day. I think that Chinese lerners will hear this common expression very often and it is very good to know this expression.