The world is updating day by day with new concepts. The automobile industry also developed new transport services with various unique technologies, which may successfully fulfill the unlimited wants and passions of the customers. The invention of automatic drive vehicles was also a good result of that worthful effort. Automobile engineers are focusing on the best performance, the safety of humans and vehicles, comfortable riding, low budget, and environment friendly when designing the new vehicle. With these situations, day-by-day manual transmission vehicles also getting disregarded from new market vehicles. Therefore, by considering the benefits of automatic drive vehicles and drawbacks of the manual transmission system, the 4-stroke 205cc three-wheel is converted from a manual transmission into an automatic transmission system with the help of rubber V-belt CVT technology. To achieve the conversion of the manual transmission vehicle into an automatic transmission, many researchers and designers have done various types of research and concepts on the different methods. Clutch actuation was used to automatically change the gears by using actuators and motors is the one concept that has less overall efficiency. The next most used concept is Hybrid Electric Technology which is already available in the market. The motors can change the gear ratio by using a motor controller which created a higher cost for the final product. The next super technology is CVT, among the various types of CVT; Belt CVT was chosen for the conversion of the three wheels. Light weight system, infinity gear ratios, simple construction, low cost, fewer alter changes for the original transmission system, easy maintenance, and comfortable ride are the key benefits that can be achieved with Belt CVT technology. The overall idea of this project is to unfasten the manual transmission system from the conventional three-wheel instead of fastening the CVT system. Here power transmission from the flywheel of the engine to the Primary pulley of the CVT is done by using a chain drive mechanism and a secondary pulley of the CVT is directly connected to the differential gear setup of the engine. The primary pully and secondary pulley of the CVT is used a Rubber V belt for power transmission. The reverse gear mechanism remained the original design of the conventional system, without any changes. According to the set of mathematical theories, the parts and equipment were selected. finite element analysis was used to design the new parts. Then all the components as per the design are mounted to the three-wheel chassis on a frame. To ensure the major goals of the project, a physically developed system is tested under some conceptions, such as fuel consumption rate per km, comfortable riding with less effort to control the vehicle, hill driving, slope driving, and a maximum speed of the vehicle. A conversion of the transmission system with CVT is successfully done by fulfilling the aim of the project and co-objectives as comfortable riding with average intermedium speed by applying less effort to handle the vehicle and developing the lighter, low-cost, compact system.