Home / Questions / What is a Peugeot e HDi? Questions What is a Peugeot e HDi? ByEditor March 28, 2020 What is a Peugeot e HDi? HDi (High Pressure Direct Injection) is a diesel engine designed by the PSA Peugeot Citroen group provided with the common rail direct fuel injection system. The first generation HDi engines were launched in 1998.