Toyota Corolla 2.0 Excel Hybrid Enormous Fuel Consumption

[FROSTYBALLS]

3 hours ago, Ampex196 said:

PS  My member profile still shows the old 2012 Auris sold last November. I'm guessing this is can be edited?

Edited for you.

[Gray86]

6 hours ago, Ampex196 said:

I have noted that the battery charge bargraph indicator on the Corolla 2.0 behaves very differently from the older Auris 1.8.  The Corolla guage rarely goes much above 50& (usually between 2 & 4 segments) while driving, though it does climb while stationery with the hybrid system running.  Pure EV mode is often not manually selectable.

With the 1.8 Auris, the indicator would cycle, generally between 40 & 90% occasionally hitting 100%. EV mode was usually available if required, eg. for car park crawls etc.

Before declaring a fault, I'd be curious to know if other owners have similar experiences  ??

Both vehicles use NiMh batteries whereas (except the saloon) the new 1.8 Corolla uses Li-Ion with a much lower capacity, ie. 3.6 AmpHr against 6.5 AmpHr for the 2.0 with NiMh.

Same experience for me, I only had a 2010 Auris for 1,500 miles before buying a Corolla. There is much more regenerative braking with the 2.0 Corolla, and it can accelerate more under electric power. I didn’t find much difference in fuel economy either between the two - shows how far these hybrids have come 

[Cyker]

Yeah, I don't remember if the previous gen ones did this as I never spent enough time in one, but the new gen ones seem to try and stick around 2000rpm as much as possible.

We've theorized that ~2000rpm is the 41% max thermal efficiency zone, so the car tries to stay there if you don't demand more torque than it can supply at that rpm, so you get this slightly weird situation where you can be cruising at 20mph, 30mph, 60mph, 70mph and it'll still be running the engine around 2000rpm  

Normally running an engine at 2000rpm at 20mph would waste a huge amount of energy, but instead the car dumps all that wasted energy into the traction Battery until it gets to a certain level, then just switches off the engine and runs off that recovered energy until it dips below a certain point, then spins up the engine again and the cycle repeats.

It's a really really clever strategy and is why, despite having such a tiny Battery, my Mk4 is still returning crazy high mpgs.

Cycling the Battery around the 50% mark will also keep it in excellent condition, as it keeps far away from the 0% and 100% charge zones where the most damage is experienced by rechargeable batteries - I think our hybrid batteries will easily outlast the battery of any pure-EV, barring an actual fault in the pack.

 

[AndrueC]

13 minutes ago, Cyker said:

We've theorized that ~2000rpm is the 41% max thermal efficiency zone, so the car tries to stay there if you don't demand more torque than it can supply at that rpm, so you get this slightly weird situation where you can be cruising at 20mph, 30mph, 60mph, 70mph and it'll still be running the engine around 2000rpm  

For what it's worth I think the Honda Jazz was the same. If you gave the accelerator pedal a gentle poke the engine would jump to 2k RPM. That was also true of the later Atkinson/Otto cycle engine. Both engines seemed to consider 2k a preferred operating point unless they were idling or being pushed.

I'm not so sure about the 1.8 Corolla. If mine needs to charge the Battery while cruising it will sit around 1,500 RPM, dropping to 1,200 when the Battery isn't being charged. However if the ICE is only running to charge the Battery it will run at 1,200 RPM.

The only thing I've noticed relating to 2k RPM is that most of the time it coincides with the start of the PWR section of the ECO gauge. That is to say that if you take the engine to 2k RPM you'll usually be just before the point where PWR lights up. Originally I thought this was the point where the electric motor started helping but a while back I realised that the electric motor starts helping somewhat before that point and (slightly to my surprise) before PWR lights up on the ECO gauge.

[Ampex196]

17 hours ago, AndrueC said:

That's much the same behaviour in the 1.8. So it must be another feature of the 2.0.

The charge gauge on my Corolla rarely reaches the top bar but it has a few times. It needs a long downhill stretch to do that and where I live there just aren't enough long/steep hills. But it's common to have all but the top bar filled in. I've hardly ever tried the EV switch but as long as the engine is warm I have no difficulty getting it into EV. Just lift off then gently reapply the accelerator, keeping the green bar on the ECO gauge within the EV section.

I don't think I've ever seen it drop below two bars.

Thanks AnrdrueC,  Your Corolla seems to read in a very similar fashion to my old Auris T-Spirit.

100% readings were rare.  All but the top one, or perhaps two bars, was common while driving.  It would drop to around 3-4 bars, then cycle back up to 7 over short periods of 10 - 15 mins.  EV mode was always available with readings above 50% indicated. This was consistent over 5 years of ownership.

The 2.0 Corolla, however, rarely goes above 5 bars (there are 8) and frequently as low as 2 bars while driving, hence manual EV mode selection is often not available when it would be useful. The gauge only ever goes up 7 bars while the car is not moving with the ICE in a typical start/stop cycle.

The Hybrid health check that is normally provided with a service did not come with the vehicle - only the stamped service book.  I'll ask Stoneacre to run diagnostics which I would hope be free of charge given the circumstances.

[Cyker]

The 'PWR' zone on the Yaris is at 3000rpm rather than 2k so I guess the Corolla's M20A is designed to run at a lower rpm than the M15A in the Mk4.

The new Honda Jazz's hybrid drivetrain seems to operate suspiciously similar to the new Yaris one; I suspect some technology licensing has been happening between them given how crap Honda's previous hybrid systems were!

 

[FROSTYBALLS]

6 minutes ago, Cyker said:

The new Honda Jazz's hybrid drivetrain seems to operate suspiciously similar to the new Yaris one; I suspect some technology licensing has been happening between them

In 2019 Toyota opened up 24,000 of their hybrid tech patents to other manufacturers for them to use, licence free, until 2030.

[forkingabout]

13 minutes ago, Cyker said:

The new Honda Jazz's hybrid drivetrain seems to operate suspiciously similar to the new Yaris one; I suspect some technology licensing has been happening between them given how crap Honda's previous hybrid systems were!

 

 

Honda have also had a lot of hybrid success / development in the last few years since they where the official power unit supplier to the Red Bull F1 family of teams. 

[AndrueC]

1 hour ago, Cyker said:

The new Honda Jazz's hybrid drivetrain seems to operate suspiciously similar to the new Yaris one; I suspect some technology licensing has been happening between them given how crap Honda's previous hybrid systems were!

I'm not so sure about that.

https://www.honda.co.uk/engineroom/electric/hybrid/all-new-jazz-technology-inside-and-out/

"EV Drive: the lithium-ion Battery supplies power to the electric propulsion motor directly.

Hybrid Drive: the engine supplies power to the electric generator motor, which in turn supplies it to the electric propulsion motor.

Engine Drive: the petrol engine is connected directly to the wheels via a lock-up clutch."

I don't think the Jazz blends power sources the way HSD does. It doesn't have an ICE-only low power option. The only time the ICE drives the wheels directly is at high speed.

From talking to people on the Jazz forum where I used to be a member it does sound as if Honda have produced a system that is more fuel efficient than Toyotas. The MPG figures are quite impressive with most people getting over 70mpg.

[Red_Corolla]

Epicyclic gearboxes traditionally provide different ratios by locking the shafts, that's how they've been used for many, many years in vehicles such as tanks and to great effect.

The Toyota version does away with clutches and achieves the same effect by regulating the speed of the attached motors. At least, that's my understanding!

[Ampex196]

1 hour ago, Red_Corolla said:

Epicyclic gearboxes traditionally provide different ratios by locking the shafts, that's how they've been used for many, many years in vehicles such as tanks and to great effect.

The Toyota version does away with clutches and achieves the same effect by regulating the speed of the attached motors. At least, that's my understanding!

More or less correct, but the torque converter played an important part.  The trad. 3 speed epicyclic trans. had 2 (wet) clutches and 2 brake bands. Both clutches engaged for high (direct) drive with both bands off.  The front clutch engaged for all fwd gears with brake bands applied for lower ratios. The reverse/high clutch only engaged in fwd. top or reverse.  They were simple and reliable with no electronics at all.  A system of valves and hydraulic pressure regulation determined the selection of ratios.

To be fair they were only suited to cars with large engines with bags of low-end torque. Still, my Rover 3.5 V8 could do well over 30 mpg on a run with around 24 mpg around the doors.

[Ampex196]

10 hours ago, Ampex196 said:

Thanks AnrdrueC,  Your Corolla seems to read in a very similar fashion to my old Auris T-Spirit.

100% readings were rare.  All but the top one, or perhaps two bars, was common while driving.  It would drop to around 3-4 bars, then cycle back up to 7 over short periods of 10 - 15 mins.  EV mode was always available with readings above 50% indicated. This was consistent over 5 years of ownership.

The 2.0 Corolla, however, rarely goes above 5 bars (there are 😎 and frequently as low as 2 bars while driving, hence manual EV mode selection is often not available when it would be useful. The gauge only ever goes up 7 bars while the car is not moving with the ICE in a typical start/stop cycle.

The Hybrid health check that is normally provided with a service did not come with the vehicle - only the stamped service book.  I'll ask Stoneacre to run diagnostics which I would hope be free of charge given the circumstances.

Some photos from today pus one historic attached.

I did manage to get it above 47 mpg where the old Auris would have hit over 70 mpg on the same mixed run.

It does have far better handling than the Auris and the 2.0 can certainly move when you plant your right foot; to the extent that I would not hesitate to overtake in situations that would be a definite NO in the Auris.

[Cyker]

Yeah the Jazz has the same MG1 MG2 setup, but they're not blended together with the ICE through a planetary gearset like Toyota does; I think the ICE+MG1 and Wheels+MG2 are completely uncoupled in the Jazz under normal circumstances, so the engine just operates as a generator to power MG2 and charge the Battery.

One nice trick it does tho' is it can drive the wheels directly from the ICE via a lockup, which removes a lot of losses from the drive train the Yaris has, although it can't drive at 70mph with the ICE at 2000rpm like the Yaris can AFAIK - It drives more like a normal ICE car with the engine varying with speed, which some people might prefer.

They've definitely done something right tho' as the level of efficiency is a huge jump from anything I've seen from them previously! Toyota's improvements have been more iterative - You can see the small improvements made with each generation. The biggest reason the new ones have such high efficiency is Toyota have made them work efficiently at motorway speeds, not just city speeds! The fact that they can now run on MG2 alone at 70+ mph really helps there, as that's something the previous gen ones just couldn't do.

It was quite close between the Yaris and the Jazz for me - The Jazz has a huge advantage in the interior space department; The back seats are much less cramped than the Yaris, it has way more storage cubbies, and it has some awesomely flexible 'magic seats' which the 'real' Yarisesisuesisess (i.e. the Mk1 and Mk2) had, and I wish the Mk4 had! In many ways the inside of the Jazz is more Yarisy than the Mk4 Yaris!

What swung it for me was the Jazz is just too long (I wanted something similar in length to a Mk1/Mk2, but set a hard-limit of 4m, which the Yaris just scrapes under), and the Yaris had muuuch better handling and driveability, but the thing that really sold it was the HUD option, which was the deal-maker for me! (I have always wanted a car with a proper semi-collimated HUD and not just something reflecting off the windscreen like those cheapo HUD kits do)

 

[Ampex196]

7 minutes ago, Cyker said:

Yeah the Jazz has the same MG1 MG2 setup, but they're not blended together with the ICE through a planetary geubikt like Toyota does; I think the ICE+MG1 and Wheels+MG2 are completely uncoupled in the Jazz under normal circumstances, so the engine just operates as a generator to power MG2 and charge the battery.

One nice trick it does tho' is it can drive the wheels directly from the ICE via a lockup, which removes a lot of losses from the drive train the Yaris has, although it can't drive at 70mph with the ICE at 2000rpm like the Yaris can AFAIK - It drives more like a normal ICE car with the engine varying with speed, which some people might prefer.

They've definitely done something right tho' as the level of efficiency is a huge jump from anything I've seen from them previously! Toyota's improvements have been more iterative - You can see the small improvements made with each generation. The biggest reason the new ones have such high efficiency is Toyota have made them work efficiently at motorway speeds, not just city speeds! The fact that they can now run on MG2 alone at 70+ mph really helps there, as that's something the previous gen ones just couldn't do.

It was quite close between the Yaris and the Jazz for me - The Jazz has a huge advantage in the interior space department; The back seats are much less cramped than the Yaris, it has way more storage cubbies, and it has some awesomely flexible 'magic seats' which the 'real' Yarisesisuesisess (i.e. the Mk1 and Mk2) had, and I wish the Mk4 had! In many ways the inside of the Jazz is more Yarisy than the Mk4 Yaris!

What swung it for me was the Jazz is just too long (I wanted something similar in length to a Mk1/Mk2, but set a hard-limit of 4m, which the Yaris just scrapes under), and the Yaris had muuuch better handling and driveability, but the thing that really sold it was the HUD option, which was the deal-maker for me! (I have always wanted a car with a proper semi-collimated HUD and not just something reflecting off the windscreen like those cheapo HUD kits do)

 

Prof John Kelly's videos are always worth a look

https://www.youtube.com/watch?v=O61WihMRdjM

[Stopeter44]

10 hours ago, Cyker said:

It was quite close between the Yaris and the Jazz for me - The Jazz has a huge advantage in the interior space department; The back seats are much less cramped than the Yaris, it has way more storage cubbies, and it has some awesomely flexible 'magic seats' ....

What swung it for me was the Jazz is just too long (I wanted something similar in length to a Mk1/Mk2, but set a hard-limit of 4m, which the Yaris just scrapes under), and the Yaris had muuuch better handling and driveability,

I could have lived with the extra length of the Jazz, +10cm IIRC, and certainly the interior management is way better than the Yaris. Living with the Yaris I'm finding it limited, it is acceptable but if I had rented and driven a few times before hand I'm not sure I would have gone for it.

What killed the Jazz as a choice for me was the (non) proximity of a Honda dealer, the closest is 80 km away, although where I used to live it was just around the corner!

I love the handling and drivability of the Yaris, but would like a stiffer feel through the steering - I haven't tried power mode, but my intention isn't to go as fast as possible on the hilly twisty and narrow roads around here.  

[Yugguy1970]

Nicest small car I've driven recently is the Fiesta Mk8.  Ford have always made good handling cars, and our MK8 Active had slightly increased ride height for comfort but didn't roll on corners.

[Stopeter44]

1 hour ago, Yugguy1970 said:

Nicest small car I've driven recently is the Fiesta Mk8.  Ford have always made good handling cars, and our MK8 Active had slightly increased ride height for comfort but didn't roll on corners.

I always loved to hate the Fiesta, but although I would complain for the first day I drove one, I was quite happy with them after that. I've rented quite a few in the past.

[Gray86]

1 hour ago, Yugguy1970 said:

Nicest small car I've driven recently is the Fiesta Mk8.  Ford have always made good handling cars, and our MK8 Active had slightly increased ride height for comfort but didn't roll on corners.

I agree - Ford have a good reputation for making cars drive well. Shame they don’t last though. . .

[AndrueC]

2 hours ago, Stopeter44 said:

What killed the Jazz as a choice for me was the (non) proximity of a Honda dealer, the closest is 80 km away, although where I used to live it was just around the corner.

For me it was few things:

My nearest dealer had been a bit lacking in care of late, as had Honda. The Mk3 Jazz just didn't seem as well designed as the Mk1 and Mk2. Hard to pin down exactly why but prior to the Mk3 I considered myself a 'Honda Jazz driver' but with the Mk3 it felt more like 'Someone who happens to drive a Honda Jazz'. Controls just didn't seem as intuitive I suppose. There were also several mostly minor issues that marred the experience.

But in the end it was the lack of a hybrid option when I was considering a change. I was also sceptical about their hybrid drive train based on the previous models so rather than wait I switched to Toyota.

[Yugguy1970]

59 minutes ago, Gray86 said:

I agree - Ford have a good reputation for making cars drive well. Shame they don’t last though. . .

Yep so we had a brand new 2019 Focus and brand new 2020 Fiesta.  Both had to have their rear shocks replaced within a year as they were weeping.   Focus needed a new accelerator assembly and new high pressure fuel rail.

Nice to drive but after that I never quite trusted the Focus.   Rightly or wrongly I do trust our Toyotas

[TonyHSD]

I have to look at Honda hybrid system again to see if it’s really as good as some people are saying. Been told previously about Hyundai hybrids are more efficient than Prius specifically ioniq, I looked at it as direct replacement of Toyota future purchase because I did tried the electric version (my gf’s car) and I did like it a lot, the hybrid is more complicated as represents two power sources plus transmission. When I compared ioniq to Prius which are very similar btw, the Toyota hybrid drive train seems the better option as it has the unique transmission without gears and clutches (+1 for Prius) and the ice has no direct injection and no belts(+2 for Prius), Battery, bms and  electric motors 20 years of experience and earned reputation for been ultra reliable  (+3 for Prius), where Hyundai has just stepped into the hybrid game and their ice are direct injection only with well known problems, plus they use dual clutch 6 speed transmission . Toyota wins for me. 🏎🏁😍

[AndrueC]

2 hours ago, TonyHSD said:

I have to look at Honda hybrid system again to see if it’s really as good as some people are saying.

FYI.

https://clubjazz.org/forum/index.php?topic=12364.0

That's a friendly forum, much like this one. Always worth posting a question as a prospective buyer.

An interesting comparison of the Jazz v Yaris later in that thread:

https://clubjazz.org/forum/index.php?topic=12364.msg102745#msg102745

Interestingly that spritmotor website puts the Jazz below the Yaris and the Corolla.

https://www.spritmonitor.de/en/evaluation/economic_models.html

[TonyHSD]

7 minutes ago, AndrueC said:

FYI.

https://clubjazz.org/forum/index.php?topic=12364.0

That's a friendly forum, much like this one. Always worth posting a question as a prospective buyer.

An interesting comparison of the Jazz v Yaris later in that thread:

https://clubjazz.org/forum/index.php?topic=12364.msg102745#msg102745

Interestingly that spritmotor website puts the Jazz below the Yaris and the Corolla.

https://www.spritmonitor.de/en/evaluation/economic_models.html

I looked quickly on Honda website and the presentation looks like Honda has very similar hybrid system to Toyota one, not sure about the engine and the transmission, e motors , drive gears, no info about that. Professor Kelley explains for the previous generation hybrids I believe, this new one seems different. I will need to look deeper when I have time. At first glance Honda seems to have it right. 👍

[bunnyrabbit03]

21 hours ago, TonyHSD said:

I looked quickly on Honda website and the presentation looks like Honda has very similar hybrid system to Toyota one, not sure about the engine and the transmission, e motors , drive gears, no info about that. Professor Kelley explains for the previous generation hybrids I believe, this new one seems different. I will need to look deeper when I have time. At first glance Honda seems to have it right. 👍

Yes, the Honda website is interesting. The key difference seems to be that the Honda system only directly drives the wheels at high(er) speeds; in all other scenarios the ICE is used to generate electricity which powers the e-motor and/or charges the Battery.

[TonyHSD]

28 minutes ago, bunnyrabbit03 said:

Yes, the Honda website is interesting. The key difference seems to be that the Honda system only directly drives the wheels at high(er) speeds; in all other scenarios the ICE is used to generate electricity which powers the e-motor and/or charges the battery.

This mode Toyota can enter when the ice is running in warming up stages and you are accelerating slow to moderate, unfortunately the Battery drains quickly and then the ice rises it’s rpm to propel the car and charging the Battery, the feeling with ice as generator and ev propulsion is really cool imo 👍 Perhaps the newer gen 5 hybrid system may offer something similar to Honda, who knows we are about to see, hopefully soon. 👌 The jazz inside looks very well made and very specious indeed. , first time a non Toyota hybrid got my attention, not that I am going to buy it, but it’s a good car , can’t deny that. 🇯🇵🚙