clipped from: www.cartuningpoint.com   
The system that helps eject out the residual particles and the burnt gases from the internal combustion engine of the car through a network of exhaust pipes is called Exhaust system. The chief usability of the whole system is in reduction of the pollutant content of the exhaust gases generated in the combustion engine. The leftover exhaust gas is vented out from an opening in the vehicle at some suitable point. During the whole discharge process, the engine power has to be as low as possible.

exhaust