给车加汽油用英语可以说成 "put gas in the car" 或 "fill up the car with gas"。
"put gas in the car" 是直译的意思，即在车里放入汽油。
"fill up the car with gas" 是一种习惯用语，意思是给车加满汽油。
来源：该短语来源于加油站或加油服务，即给汽车加满汽油。
例句：
Can you please put gas in the car?
(请你给车加汽油好吗?)
I need to fill up the car with gas before we go on our road trip.
(我需要在我们旅行前给车加满汽油。)