Honda v. Toyota hybrid system

[Hugh R]

Can someone simply sum-up the essential difference between the two latest versions - and perhaps what the Honda might gain over the Toyota.

[richardfrost]

The Toyota system uses the electric motor to boost the petrol engine to keep the petrol engine running at it's maximum efficiency. So it helps out with acceleration and cuts out the petrol engine when coasting is possible and uses the electric system to nudge the car along and maintain speed.

The Honda system uses the electric motor as pretty much full time drive and uses the petrol engine to keep the battery charged up and also uses it when high speeds or hard acceleration need to be maintained in order to avoid excessive battery drain and provide additional motive power.

Both systems aim to use the petrol engine at the peak of efficiency. The difference is in the final drive to the wheels and the balance between electric and petrol engine power.

Both systems should not be confused with battery electric vehicles, which have no petrol engine and rely entirely on power stored in the batteries and regained from kinetic energy. Both hybrid systems can only provide pure electric drive for short distances measured in metres rather than kilometres.

[Kremmen]

From what I've read the Jazz 4 pot engine is far more refined than the Yaris 3 pot.

[toolroomboy]

I believe the Toyota has a gearbox doesn’t it?

[Pine]

Toyota hybrids do not have a gearbox, there is no direct drive between the engine and wheels.  I have a Toyota Corolla but I don't know the technical details of how it works.  Like Honda, Toyota call it an e-CVT although it isn't a CVT in the conventional sense but when it is driven it can behave like one.  Depending on throttle position and whether the hybrid battery is being charged the revs at a steady 60 mph can be as low 1000 rpm, or even zero if it has switched to electric mode under very light load, whereas I understand the jazz at the same speed has a direct link from the engine to the wheels.

[Kenneve]

The Honda system is far more refined than some have said, starting off in EV mode and as speed increases it seamlessly switches to Hybrid mode and at high speed it is purely in ICE mode.
Generally from cold, the engine will start up straight away, to provide cabin heat and ensure that the HV battery is in a good state of charge.
The switch from ICE to Hybrid or EV, depends entirely of road conditions and power demand and the driver has no control, on when those changes take place.
It is perfectly possible to travel at 70mph in EV mode for short distances.
Today on the M1, I was in EV mode at 70mph, several times for short distances, maybe 1/2 - 1km or so, generally on slight downhill slopes.
Yes, at around 60mph the car will usually be in ICE mode, but if conditions require addition power, (to overtake etc) it will change back to Hybrid mode, with the ICE speed rising to generate the power.

[Jazzik]

I believe the Toyota has a gearbox doesn’t it?

The Toyota Hybrid "gearbox" looks like this:

It's this BIG!!!

It's a power split device. How it works you find here:

[toolroomboy]

How is that dealt with in the Jazz?

[madasafish]

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.

See "sum of the parts2  - 5 pictures 2/3  way down page.
https://www.honda.co.uk/cars/world-of-honda/present/hybrid/performance.html

[John Ratsey]

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:

[Hicardo]

wow, that you tube video and explanation was excellent..thanks for posting.  There's a lot of engineering going on there.....

[Expatman]

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!

[Saycol]

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!

Agreed. Most say it has a CVT gearbox and clearly it hasn’t!

[Gas Jazz]

As shown in the WeberAuto youtube video linked by John R, there are no changeable gears in the e ECVT.

The final drive is a fixed final ratio determined by reduction gears engaged in either engine drive of motor drive mode as appropriate.

Hence the only “gears” are those in the reduction / engagement train which result in a single fixed ratio.

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!

[John Ratsey]

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.