Environmental concerns combined with strict emission regulations, inspired the automotive industry to investigate more efficient powertrain technologies including downsized engines, Atkinson-Miller engines and electrification of powertrains. Although these technologies offer improvements in official fuel consumption tests, their benefits in real driving conditions can vary significantly due to large variations between the actual driving conditions of drivers and standard driving cycles. Therefore, it is important to assess these technologies in various driving cycles with different characteristics and this paper aims to offer an overall perspective on the matter with a simulation analysis. The simulations are carried out using GT-Suite computational software, employing a passenger car model with six configurations, including a conventional spark ignition (SI) engine, an SI engine with a start-stop system, a downsized engine with a turbocharger, a Miller cycle engine, a hybrid electric vehicle (HEV) powertrain and an electric vehicle (EV) powertrain. They are tested in six driving cycles including NEDC, WLTC, FTP75, NYCC, HWFET and US06, where the impact of different technologies on equivalent fuel consumption are analyzed, with respect to different operating conditions. Initial results reveal that, a combination of certain driving cycles and vehicle configurations have a large impact on fuel consumption. HEV and EV configurations offer substantial improvements compared to baseline SI engine in city cycles, but their benefits are reduced at cycles including high speeds. Miller and downsized engines offer some improvements in all cycles in general while the start-stop system only has some benefits in city cycles with frequent stops.