Hybridization of a light duty diesel vehicle based on two new different power train concepts for a parallel hybrid vehicle is discussed. The paper focuses on the design, development and performance evaluation of two new parallel HEV power trains. The diesel electric hybrid vehicles are different from other hybrids with regard to the power train. Two new hybrid drive-trains namely, a post-transmission architecture using an additional simple PGT, and a coupled PGT based parallel hybrid transmission are designed. To demonstrate the practical applicability, two research prototypes equipped with these power trains are built with the same degree of hybridization. The implementation of the new designs enables to overcome many problems encountered in the traditional vehicles. Among the various control strategies, a rule based control strategy is considered for the hybrid vehicles. The prototypes of hybrid electric vehicle are tested on chassis dynamometer and test tracks. Drive cycle used for testing of the vehicle is also discussed. Test results are analyzed and compared to an emulated diesel vehicle. The performance parameters include fuel consumption, mass emission, maximum speed and vehicle acceleration. Possible modes of operation in the intended configurations are also stated. Even if one system (the electrical system or the IC engine) fails, still the vehicle would remain functional on the other system. Based on this study, hybrid powertrain strategies for future vehicles are proposed.