The Purdue EcoMakers have selected the Parallel-through-the-road (PTTR) PHEV as their final EcoCAR 2 architecture. In the context of the 2013 Malibu, the parallel-through-the-road architecture offers the ease of integrating an independent parallel electric motor to drive the rear wheels, significantly reducing packaging concerns in the front. The front drivetrain can be kept similar to the existing Malibu drivetrain, but coupled to a donated GM 1.7L Diesel engine instead of the larger 2.4L Gasoline engine on the production Malibu. 

"The parallel-through-the-road architecture allows us a lot of flexibility in our control strategy, to leverage direct propulsive power from the 1.7L diesel engine as well as the Magna E-drive motor, but without the control and integration complexities associated with a conventional power-split device or a pure parallel architecture. With this architecture the Purdue vehicle will have a significant pure electric driving range which is crucial to the EcoCAR 2 competition goals," Ashish Vora, Technical Team Leader.

The 6x15s3p A123 battery pack and battery management system will constitute the Energy Storage System (ESS) for the electric drive train. This consists of a 45kW continuous power Magna e-Drive motor donated by Magna, coupled to the rear wheels via a custom designed final drive. Plug-in capability will be provided to the vehicle through the donated Brusa charger. 

Thus in charge-depleting mode, the vehicle will be propelled solely by the electric rear drive train, which can be supplemented by the Diesel engine powered front drivetrain if the acceleration demand is very high. Once the battery charge is depleted, the front drive train will take over and the vehicle will be powered solely by the Diesel engine. The rear drive train will continue to function for regenerative braking, and supplementing the engine for brief periods of high acceleration demand.