48V mild hybridisation of powertrains is set to become commonplace over the next 5 years, providing a significant proportion of the on-cycle and real-world CO2 benefits of a high-voltage hybrid at a far lower cost. However, the majority of this focus is around engine-related systems such as belt starter-generators and electric-boosting.Simon Shepherd and Sam Fraser will be discussing aspects of their current research at DSD, looking in more detail at this subject; discussing the potential advantages of using the hybrid motor functions to take cost out of the base transmission as well as the use of a passive freewheel coast concept enabled by smart engine and motor control.