Turbocharged CI engines have for a long time been the standard propulsion unit for Heavy-Duty vehicles. In recent years, vehicle electrification has been a growing trend, especially for passenger cars, but also for city buses, and the trend is now carrying over into the heavy duty segment. When electrifying the powertrain there arises an opportunity to revise the traditional turbocharging trade-off between fuel-economy and transient performance. The trade-off can, with the help of electrification, be made in favour of fuel economy since transient performance is improved by the electric machine. The paper investigates this trade-off by looking at four CI powertrain concepts. A conventional powertrain for reference, a conventional powertrain with an oversized turbocharger, an electrified powertrain with a standard CI engine, and an electrified powertrain with an oversized turbocharger. The concepts are evaluated on the following cases: stationary operation, tip-in and tip-out, acceleration and retardation on flat road, acceleration and retardation in an uphill, and hill climb and hill descent. The investigation is based on a validated mean value engine model of a heavy duty six cylinder inline CI engine, and on a validated driveline and vehicle model of a heavy-duty truck. The evaluations are made with the help of simulations and numerical optimal control. A sensitivity analysis is performed and the results show strong impact of electrification and turbocharger selection.