A powertrain includes an engine that has a crankshaft. A first motor-generator is drivingly connected to the crankshaft via an endless rotatable device. The powertrain includes a transmission that has a transmission input member driven by the crankshaft and a transmission output member. A front differential is operatively connected with front half shafts. A transfer case is configured to distribute torque of the transmission output member to the front differential and to a driveshaft. A rear differential is configured to transfer torque from the driveshaft to rear half shafts. A second motor-generator is drivingly connected to the rear differential. A gearing arrangement is configured to multiply torque from the second motor-generator to the rear half shafts. A controller controls the second motor-generator to function as a motor that provides torque to the rear wheels through the rear differential. A modular rear drive unit operatively connects to the vehicle body.