Gasoline engines require oxygen to run.
Without oxygen the engine would die out and not run.
For example if you choke an engine with a carburetor the engine will usually shut off as it needs the air and oxygen to enter the carburetor and throttle body to allow the gasoline to ignite and combust.
A a combustion engine requires oxygen for the combustion reaction.
This oxygen is generally obtained from the atmosphere, but can be supplied as a compressed gas or in liquid form in some instance.
Beyond the combustion stroke, which pushes the piston down from the top of the cylinder, there are three other strokes: intake, compression, and exhaust.
Engines need air (namely oxygen) to burn fuel.
Although there are many different designs to an internal combustion engine, there are three crucial components needed to make one run, a fuel to burn, oxygen to support combustion, and an ignition source to start combustion.
The engine can burn no more gas than the amount of oxygen allows.
Any extra fuel would come out of the exhaust pipe unburned.
So if the car used pure oxygen, it would be inhaling 100 percent oxygen instead of 21 percent oxygen, or about five times more oxygen.