“I thought they use some sort of special planetary gear arrangement for the hybrid drive. Can a manual even work with that? “ – IceAndFire
No, Toyota’s planetary gear system is very elegant as it can handle one, two or three power sources rotating at various rpm without requiring clutches. It can also turn either of the two electric motors into a generator without any additional mechanism. The gearset is a kind of CVT and does not require additional transmission. Honda, Hyundai and Infiniti, on the other hand, are using different hybrid system, in that ICE output shaft is connected coaxially (in tandem) to an electric motor, technically the output of which can be connected to either manual or automatic transmission in conventional fashion. In the case with manual transmission it requires a usual clutch. When coasting or stopping the electric motor turns into a generator to recoup energy, in which case a clutch to disengage ICE and electric motor(generator) would be a good idea for more efficient energy recovery. Hyundai and Infinity are using this clutch system. Honda cannot put a clutch between the ICE output shaft and the pancake flywheel-motor and instead closes all the valves to reduce drag. I think eventually Honda will also put a kind of clutch (sleeve type?) to make its hybrid system more efficient.
The tandem ICE/motor design is more desirable for sports oriented vehicles because the speed (feel and sound) of the ICE/motor is in sync with the acceleration of the vehicle. Toyota’s FT-86 and Subaru’s twin as well as future Mazda RX-8 replacement are supposed to be “sports” type. Because of the short length of their ICE I think eventually they will all come with a hybrid version with the tandem ICE/motor design.
