The Prius' drivetrain system was designed to split the power generated by the axle that drives the car and the generator that powers the batteries. It features a planetary gear system to manage power distribution smoothly and precisely. The group working on the gearbox had tried various system designs to decide on compatible dimensions that would fit into the small space available, as the dimensions of the car body were already fixed and it was very compact in nature. Some design changes were made against convention, such as mounting the engine and gearbox on the side as the engine compartment had a limited length to accommodate it otherwise. At this point the technical problems were numerous as the engine, power splitter, generator and other devices had to be placed in line and there was simply not enough space for them. The only feasible and practical solution was to detach the decelerator from the power distribution device and connect it with a chain drive and a 20 mm wide chain was used for this very purpose. The system now fit almost perfectly into the allotted space