no
No. not earthly vehicles. Some spacecraft have ion engines (at least they have been proposed).
It could be condensation from hot exhaust gases on the cool exhaust pipe.
It superheats exhaust gases and burns any unburned gases to clean up the emissions escaping from the tailpipe.
The primary exhaust gasses of the internal combusion vehicle are carbon dioxide, carbon monoxide, and water vapor.
There is only 0.4 percent of oxygen in the car exhaust gases coming out of a car engine because most of it is used up in the combustion process. Exhaust fumes also contain carbon monoxide.
As a rule exhaust is emitted on the opposite side of the fuel filler tube on single exhaust vehicles for safety reasons.
O2 sensors are located on the exhaust system in todays vehicles, they monitor the oxygen levels in the engines exhaust gases. They send that information to the vehicles computer which inturn regulates the engine's fuel system for a clean burn.
An exhaust system has 3 main effects - it ensures combustion gases are safely removed from the vehicle, away from occupants, air intakes etc., it reduces noise from the engine (silencers/mufflers), and it controls the pressure on the exhaust side of the engine. In some vehicles the exhaust gases will also drive a turbo-charger.
Main gas is CO2. Gases like SO2 also can be produced
When the engine of a vehicle consumes fuel and air to generate energy, the vehicle cannot retain the products of combustion; it would be too inefficient and expensive. The vehicle discharges those waste elements in the exhaust system. The exhaust gases are carbon dioxide, carbon monoxide, nitrous oxides, water vapor and soot.
It is necessary for the evaluation of air pollution by exhaust gases.
EGR uses exhaust gases for decreasing the pollution levels. Here the exhaust gases are actually fed to the precombustion chamber or the ignition chamber. In a turbocharger, the energy of the exhaust gases is used for compressing the ambient air, and the exhaust gases are then released.