An apparatus includes a drive shaft, a transmission, a motor shaft, and an engine shaft. The drive shaft includes several drive gears and is used to transmit power to a wheel of a vehicle. The transmission includes a first transmission subassembly and a second transmission subassembly, each subassembly having a transmission shaft, an input gear, and several output gears. Each transmission shaft includes a shifting element to select an output gear. Each transmission subassembly transmits power to the drive shaft when the shifting element of each respective subassembly is engaged. The motor shaft is coupled to a motor and is also directly coupled to the first transmission subassembly via a first motor gear. The motor shaft is also coupled to the engine shaft via a second motor gear. The engine shaft includes several engine gears to couple the engine shaft to the first and second transmission subassemblies.