It’s an aerosol, fine droplets of liquid in a stream of air. It used to be the carburetor that added the fuel to the airstream (by way of the Bernoulli principl

It’s an aerosol, fine droplets of liquid in a stream of air. It used to be the carburetor that added the fuel to the airstream (by way of the Bernoulli principle); modern cars use a fuel injector, which works on much the same principle as a spray bottle to create the fuel-air mixture directly in the cylinder.