This is a common misconception that the transmission is a part of the engine. They are definitely correlated but the transmission is definitely not a part of the engine. They are two different parts, and these units have their own function that differentiates them from each other. Even though they are different both of them are essential to the power of your vehicle. The engine is responsible for providing power to the vehicle while the transmission manages the output of the engine as well as the driving conditions. The engine is the heart of the engine that helps move the vehicle on the road. It also helps to power the various accessories that come with the engine. The main function of the engine is to convert the chemical energy extracted from various fuels into mechanical energy to move the crankshaft.