The racial taunts prompted Kanak Hirani to throw them out of his vehicle. The passengers even did not pay the fare.
Hirani picked up the group in Cardiff city centre in Wales last week.
He drove them to a cashpoint and the passengers then asked him to take them to the McDonald's restaurant before going to their intended destination.
'WalesOnline' reports that two of them went into the restaurant to pick up the food while the other two stayed in the car.
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He told the newspaper: "The passenger sat in front spat on the floor. I asked him why he did it and he said he didn't do it. I pulled over and said I wanted something up front because I'd rather lose a 20 pound fare than a 45 pound fare.
"They said they had the money and would pay me when they got up there and they gave a little verbal abuse to me. They threatened to knock me out. I said there's no need for this and I said that I didn't know them.
He has since reported the incident to the police, as well as passing on video footage of the incident.
He describes them as white, with brown and blonde hair, and were wearing jeans and t-shirts "I want these guys prosecuted", Hirani said.
A South Wales Police spokesperson confirmed they are investigating the alleged incident.
"Police in Cardiff are investigating allegations of racial abuse and failure to pay a taxi fare following an incident which happened shortly after 4am on Friday, December 4," he said.