I believe the Toyota has a gearbox doesn’t it?
Dealt with in the Jazz with lots of gears which engage under certain conditions and an engine linked clutch for direct drive of the wheels by the engine.It has very few gears with most of the difference between engine speed and road speed being handled by the electronics except when in the direct engine drive mode. See these two videos to help understand what's under the bonnet:
I just wish the major Motor magazines car reviewers would watch those videos so they understood the way the Honda hybrid system works. It is patently obvious from the reviews I read both on-line and in the magazines that few, if any, car testers have any idea how it works!
Therefore when in engine mode the “gear changing engine noise” you hear is simulated as there are no gears in the transmission to change! I have no idea why Honda in their wisdom chose to include this feature unless they thought it would sound sporty and be attractive to the driver!There's the perception that drivers are annoyed by the continuous changing of engine revs without the corresponding change in vehicle speed which is a characteristic of CVT transmissions as the engine tries to match its power output to the road conditions. Hence, unless in direct drive, the engine appears to have some preferred operating speeds and jumps between them. There may also be some science behind this as the designers have tried to configure the engine to operate at maximum efficiency at certain revs. The best efficiency is at around 2000 rpm as shown in the first video. However, there could be another optimum operating speed in the higher power output zone.
However, for the Jazz e CVT when in engine mode the engine is “locked” to the drive wheels by the fixed ratio reduction gears - a bit like riding a single speed bicycle. This being the case I’m not sure how revs can be optimised without impacting on road speed.I suspect that such optimisations are matters of a few percent which help the overall mpg, but are less than the efficiency gain by using direct drive which avoids the generator / power conversion / motor losses.
I also wonder if the generator is also used in reverse as a starter motor for the ICE.Yes. Both motors can be used as generators or vice versa. Hence the term "two motor hybrid" although, at any time, only one is a motor and the other a generator.
I cannot get over how seamless the whole thing is between the engine and battery power, it is a clever piece of technology.
That's because in all conditions except high speed cruising, the car is driven by the electric motor, with power coming from either the battery, or the generator, or both. The only time the car is driven directly by the engine, is in cruising speeds above around 55mph, when a clutch closes to provide direct drive..
I've also seen the cog with electric assist.Not sure about that.
I've seen both. There can be direct drive with a trickle of electricity being used to get the battery charge up to 70% and there can also be direct drive with some assistance from the battery (eg for some acceleration or adverse gradient). Once the battery gets to 30% charge and if more power is still needed than the engine can produce at the revs determined by direct drive then the vehicle will switch to electric drive.I've also seen the cog with electric assist.Not sure about that.
Page 7 Engine (Direct Drive), of the Power Flow display, shows the Engine driving the car (with cog), but the HV Battery is being charged, not discharged!