The power that the engine develops is delivered to the driving wheels of the automobile by the power train (drive train). The transmission is a major part of the power train and its job is to multiply the torque developed by the engine. The transmission and the differential compose the two sets of gears in the drive train. The transmission adjusts the gear ratio while the differential lets the drive wheels turn at different speeds. The transmission changes speed and power between the engine and driving wheels of a vehicle. Front wheel drive cars combine the transmission and the differential in one housing to form a transaxle. Figure 9.10 illustrates a basic drive train configuration.