If a car uses compressed air engine it can reduce about 20% of the total cost of production because it doesn’t have cooling system, fuel tank, sparking plug and silencer etc….The exhausted gas from the cars has a bad effect to environment but compressed air engine doesn’t exhaust noxious gas, therefore this engine can solve the problems of environmental pollution….Compressed air engine is operated during the start, acceleration or going up a hill where the electric motor consumes a great deal of power rapidly. The compressed air engine converts back to the electric motor when the vehicle reaches a speed of 20-25 km/h.