Abstract: Now a days we are facing a lot of problems with respect to fuel demand. A common problem is how to increase engine efficiency? and how to manage the fuel economy?. Etc...So, the objective of this project work was to gain a better understanding of the efficiency characteristics of engine with inlet air pre heater. For this purpose, the effect of inlet air pre heater orientations, no. of testing, types of sophisticated fuel, types of material used for the purpose of inlet air pre heater have been investigated. In this project, we modified the air intake into the cylinder of four stroke air cooled IC engine of 2 wheeler, to improve the fuel vaporization rate, proper combustion &increase the fuel efficiency. The preheating of intake air is achieved by introducing an air pre-heater in the exhaust pipe (silencer) of the vehicle. Fresh air takes heat from heated silencer and this heated air send at air chamber. Because of this heating of air fuel vaporization rate gets increases which results in above advantages.