Honda has an interesting solution in their latest gen hybrids, where the electric motors power the wheels at lower speeds, the combustion engine runs at its opt

Honda has an interesting solution in their latest gen hybrids, where the electric motors power the wheels at lower speeds, the combustion engine runs at its optimum RPMs as a generator while the electric motors are working, and at higher speeds a clutch activates that changes the coupling so that the combustion engine directly drives the wheels.