With the implementation of Proconve P7, several challenges were faced regarding the integrity of the Power Cell Unit (PCU), which comprehends pistons, rings, cylinder liners, pins, conrods and bearings. The technologies of reducing NOx affect directly the performance of these parts. The systems focused on EGR (Exhaust Gas Recirculation) provoke a higher level of soot contamination in the oil, which creates to all the PCU an abrasion mechanism that leads to the increase of wear load. The systems focused on post treatment of the exhaust gas enables to reach higher PCP (peak cylinder pressure) and higher temperature of combustion. Such conditions are also critical to the PCU combustion, which needs to increase resistance to higher mechanical and thermal loads.Using the experience of Europe and NAFTA some expectations about the environment conditions of Heavy Duty Diesel (HDD) engines after Proconve P7 can be discussed. The main PCU challenges are described in an environment that basically may constitute on the combination of EGR and post treatment technologies. It can also demand a significant discussion about other characteristics linked to green house gases and/or fuel consumption.On the PCU components some challenges can be summarized among improved wear resistance materials, improved fatigue resistance from the use of material and design solutions, and reduced friction and consequently reduced fuel consumption.Results of numerical simulation, bench tests, metallographic analysis and engine tests are presented to support the discussions.