"Hybrids can't possibly use less fuel than a conventional ICE.."

[Stopeter44]

8 minutes ago, TonyHSD said:

... yes they are more efficient than ice cars , ok diesels can get close or even slightly better in specific conditions like long motorway drives but that’s it once you hit the traffic jams or get into town your efficiency disappears, plus they require a lot more unnecessary maintenance and parts replacement. Here it is why Prius is till preferred car for many taxi and delivery trade. 

That's so true about diesels, in city traffic I think they take more fuel than standard ICE of similar capacity.

[Cyker]

Must admit I've never heard of anyone say a hybrid can't use less fuel than a normal ICE - Usually it's just that they're boring and slow! I can understand why - The early ones weren't exactly sprightly, but that was decades ago! Things have changed a lot since then, and the new TNGA hybrids are definitely not boring or slow  

Diesels are still much better than normal petrols for idling - They don't have to deal with the significant parasitic loss from a closed throttle like petrol engines do. My old Mk1 was returning 63mph on average for the same driving conditions I'm getting 75-80-odd out of my Mk4 - Not bad for a near-20 year old car!!!

The demonizing of diesels is a damned shame IMHO - With more R&D to make it burn cleaner without needing things like the EGR and DPF, which basically ruin them, I'm sure it could be brought up to modern emissions standards without impacting the reliability so badly. If they could also then optimize it for use in a hybrid you'd get a car that could easily hit 150+ mpg during normal use!

But that's by-the-by now - R&D into ICE is in sharp decline as everyone tries to pivot to EVs and H2. It's one thing I hate about the ICE ban that's coming - So much knowledge, that could still be useful, is going to be flushed down the toilet!

[RickyC]

1 hour ago, Catlover said:

Just seen you from Italy. How long is the standard warranty on a new car? In the UK it was 5 year, but from July 1st this year it has been reduced to 3 years. Relax can be taken after the end of either 5 or 3 year standard warranty.

In Italy standard warranty is 3 years on engine and not hybrid components and 5 on hybrid part ( Battery, inverter, electric engines... ) then starts free relax for standard components ( if you have regular checks every year or 15.000 km ) till 10 years or 100.000 km.  For Hybrid Battery after fifth year theres a free warranty year if Hybrid Check is succesful. Hybrid check is  free in case of regular checks or 60 euro in case of no regular maintenance checks.

The warranty ( extended one included ) is transferred if you sell the car.  In any case the maintenance history is not regular you can start extended warranty also later with a maintenance by a Toyot dealer but it's no operative for the first month.

Unluckly extended warranty doesn't cover LED lights, and I fear that you can't change just the lamp.

[CPN]

3 hours ago, Roy124 said:

NGR, you REALLY wanted an essay? 😊

No but I would agree with Nick, Roy? You did over simplify it and left out quite a lot of pertinent detail in your summation. I doubt that your conclusion, if using the new Mk4 or even the Mk3 Yaris, would stand up. For example, the extremely thermally efficient ICEs that Toyota produce as part of their hybrid drive train. ICEs that can switch very cleverly and seamlessly between Otto and Atkinson cycle and this also has quite a bearing on final fuel consumption of their Hybrid vehicles. I believe that I am right in saying that Toyota are well up into the top 5 of world manufacturers when it comes to the thermal efficiency of their ICEs... Especially in their new TNGA platformed cars. Yes, their Hybrid systems seem to be overly complicated but they are like that for a good reason, they have the most experience worldwide on hybrid drive train production and I would argue that they are probably the best...

[Rosgoe]

17 hours ago, yossarian247 said:

More of a general rant than anything specific to the Prius, but does anyone else encounter people in everyday life who will try to tell you in great detail that hybrids are a con because they can't possibly achieve better fuel consumption figures than a conventional petrol engine?! They then often go on to give various spurious 'scientific' reasons of why they are right.

Clearly myself and various friends and family who easily achieve 60+ MPG in our hybrid cars are all just imagining it! 

I wouldn’t say I can easily achieve 60+ with the auris in the summer months I could,with the corolla have done 2600 miles average fuel consumption 59.8 and I know that if I work it out on tank full to tank full that will drop down to 55 ish. In the winter that drops down to the high 40’s and I do not drive quickly 65 on the motorways 50 to 60 on a and B roads.

I had a 1.9 tdi golf as a second car non dpf and that would easily achieve 65 + but as tony hsd has said you have the extra maintance costs and diesel is more expensive.

[Stopeter44]

1 hour ago, Cyker said:

But that's by-the-by now - R&D into ICE is in sharp decline as everyone tries to pivot to EVs and H2. It's one thing I hate about the ICE ban that's coming - So much knowledge, that could still be useful, is going to be flushed down the toilet!

And me, I just wondering about Atkinson vs Otto and 14:1 compression ratios and E10 fuel.

On the subject of knowledge, Just think of all those poor blacksmiths and coal miners from a bygone age ...

[FROSTYBALLS]

The new car warranty in Italy and France is 3 years/100,000km, with hybrid components covered for 5 years/100,000km - which is the standard now across Europe. The Relax warranty comes into effect after the new car warranty expires, subject to the required servicing via the Toyota dealer network.

In the UK the hybrid Battery extended warranty can be extended up to the vehicle's 15th birthday.

[AndrueC]

I've not met any rabid haters yet but I've met a few who were intrigued about how it was possible. Luckily I know enough to explain how it works. The basic premise of the hybrid system is threefold:

• To try and always run the ICE at the most efficient point of its power curve including:
  • Overrunning the ICE and storing the excess energy for future use.
  • Underrunning the ICE and using stored energy to compensate for the lack of power.
• Allowing the ICE to be switched off completely at low-loads when it operates at its least efficient. The energy then used to move the vehicle was mostly generated at a time of maximum ICE efficiency or is reclaimed energy.
• To minimise kinetic energy loss by recovering some of it and storing it for future use.

Another advantage (which I tend to ignore because I feel that it's wasteful) is that it allowed Toyota to fit a weedy but efficient engine into the car knowing that the stored energy could provide a boost for heavy-footed drivers.

[AndrueC]

9 hours ago, Stopeter44 said:

The bit that most people with no knowledge of hybrids miss, is the regeneration of battery charge when breaking or coasting.

I'm not sure about that. When I was looking into hybrids it was the bit I focused most on. In fact one of my concerns was that because I use the brakes so rarely the Battery would never have much of a charge in it.  Having owned a hybrid for over two years now I know that only a small amount of the Battery charge comes from reclamation. Most of the energy in the Battery comes from the ICE driving the electric system as a charger. 

My post above explains why that reduces fuel consumption 😉

[yossarian247]

Thanks for all of the replies! Always interesting to hear different viewpoints and experiences.

 

Until summer last year I had no personal experience of hybrids, however I knew a few people who did and they really liked them so when my wife needed a new car we thought we'd try a C-HR hybrid. So far we have been very impressed with it, and I'm perhaps exaggerating to say that we always get 60 MPG, but we generally at least 55 with no problem.

Of late I seem to have encountered quite a few people who are 'anti-hybrid' for whatever reason. Often the reasons are pretty strange and illogical. For example someone I work with previously owned an Auris hybrid, but said she didn't like it 'because the petrol engine kept starting up all of the time'. So what did she replace it with, an EV? No a 1.2T!

A relative of mine considered a Pruis but discounted it after looking under the bonnet of one because 'its got two engines, twice as much to go wrong..'

What really prompted my post though was someone I encountered on Facebook recently. I was idly glancing at an ad for a Merc plug-in (no intention of buying one btw) and spotted an absolute essay of a comment below it. Someone had gone to some considerable time and trouble to write a lengthy post about what a total con hybrids are, and that they actually use more fuel than a conventional ICE. They quoted all sorts of laws of physics and even gave an equation to demonstrate their point. I should have known better than to engage with an obvious pillock but sometimes I just can't help myself!

Their point was basically this: A conventional car uses X amount of fuel to cover a given distance. Due to the additional weight of the motor, batteries, inverter etc, a hybrid uses X + Y fuel to cover the same distance, with Y being the extra fuel required to lug the electrical gubbins around. Although the hybrid can recover some of the energy of Y, it can't recover any of X..so it actually uses more fuel than a normal ICE..

I replied saying that, yes although the hybrid may well be heavier, it can recover some of the energy of both 'X' and 'Y' in his example. Over all the greater efficiency more than makes up for the extra weight, so despite the extra weight you still tend to get much better fuel consumption than a conventional petrol.

His reply to this was various patronising emoticons and 'No it can't recover more energy than it uses, that would be breaking the first law of thermodynamics'. I tried to explain that that isn't what the first law of thermodynamics says at all, and that I wasn't suggesting that the hybrid system somehow creates energy out of thin air, it merely recovers energy from the ICE that would otherwise have been wasted as heat. He wouldn't have it though! I think we have all met the type who constantly refers to 'the laws of physics' but when asked to explain any of those laws clearly has no idea what they are talking about 😅

 

[CPN]

That is a spot-on post, Nick! lol!

[yossarian247]

3 minutes ago, CPN said:

That is a spot-on post, Nick! lol!

What particularly made me smile was his idea that presumably when you press the brake in a hybrid the regenerative braking system somehow thinks to itself 'Right, I'm going to recover some of the energy from slowing down the mass of my hybrid system, but I'm definitely not going to touch any of the energy from slowing the rest of the car down, that energy is nothing to do with me, if i recovered any of that i'd be breaking the laws of thermodynamics, I'd better leave that bit to the friction brakes..'

[CPN]

One of the biggest differences that I have noticed between my previous Mk3 Yaris Hybrid and my new Mk4 is the Battery technology and how Toyota has taken advantage of the change from Ni-MH to Li-Ion in the new Mk4s.

Since I make regular use of the excellent Android App "Hybrid Assistant", I have been able to see this in practice. The thing about this app is that you are able to actually see the power consumption and reclamation in real time of the HV Battery in Kilowatt units on the display. You are also able to see the Kw output of the ICE in real time also for comparison...

In the Mk3 (Ni-MH), the system used to follow a quite narrow window of between 40% - 60% (sometimes reaching 65% but not often) SoC during driving. Also, the reclamation either via braking or the ICE itself actually topping up the HV Battery was much slower since this is the nature of Ni-MH batteries i.e. they take longer for a given input to recharge than Li-Ion.

The Mk4's Li-Ion batteries are so much better in that they recover faster and can withstand a higher charge rate. They seem also to be able to release better power at lower SoC levels than the Mk3's Ni-MH batteries. With the Mk4, I have seen the SoC go as low as 25% before the ICE kicks in and reach as high as 76% during braking regeneration. For example, when I was out yesterday and I started braking going downhill, if I played with the brake pedal, I could get the HA app to show 34Kw being fed back into the battery before mechanical braking took over. This manifested itself in surprisingly hard braking given that it was only as a result of the electric traction motor being "reversed". The most I ever managed with the Mk3 was 20+Kw of reverse charge in that way. I think that this is just one of the reasons why the Mk4 Yaris is so much better/more efficient than the Mk3. i.e. the working range and available power from the HV battery is much wider because it is better technology.

My own conclusion in all this about the Toyota Hybrid drive train methodology is that to over simplify such a complex system is to completely miss the point and sophistication of such a system.

[TonyHSD]

Those guys were saying that hybrids are pointless and use more fuel than standard ice cars are actually right and the only hybrids that are more efficient than standard ice cars and make sense buying and driving one are Toyota self charging hybrids and perhaps a very small number from other manufacturers can also be considered like Hyundai and Honda but these although can match Toyota efficiency they are far behind in terms of drive train simplicity and reliability, plus maintenance cost in a long run. They do have slightly  over complicated tech but the German ones they are full stop. If you about to buy a new Mercedes just buy a diesel one, if you about new Toyota buy hybrid and if you about a new electric car get a Tesla , it can’t be easier than that 😉👍

[Yugguy1970]

Agree with CPN there.   These are amazing engines developed over decades.

I think the same when I read threads on here about people basically trying to second guess the system.    Don't do it, just drive it and let the computer worry about it.

[CPN]

5 minutes ago, Yugguy1970 said:

Agree with CPN there.   These are amazing engines developed over decades.

I think the same when I read threads on here about people basically trying to second guess the system.    Don't do it, just drive it and let the computer worry about it.

Bingo! Exactly!!

[Roy124]

CPN, I was arguing for THICE with essentially diverting lost thermal energy to Battery storage.  Anything else it just engineering, weather, or external factor variation. 

[CPN]

11 minutes ago, Roy124 said:

CPN, I was arguing for THICE with essentially diverting lost thermal energy to battery storage.  Anything else it just engineering, weather, or external factor variation. 

It's that phrase in red above that I have a problem with and especially the word "lost"? It is not "lost" as such. It is very much a calculated commodity in the Toyota Hybrid scheme of things. Also, that word "just" in the second sentence is a bit dismissive of an extremely complicated and technologically advanced system don't you think? Just my opinions...

I would really like to enact your "test" as you originally described it because I think you would be astonished at the result! (and not in a good way from your perspective...)

[Cyker]

The funny thing with hybrids engines is they are NOT inherently more efficient than normal petrol engines - Granted the newer Dynamic Force engines are getting close to diesel-levels of efficiency from 20 years ago, but the best theoretically possible petrol engine will never reach an equally theoretically best possible diesel engine in terms of efficiency - The diesel cycle is just more efficient, end of.

No, the main strength of Toyota's hybrids is they are extremely good at recovering energy that would otherwise be wasted, and there is a lot of it!

I can only speak for my Mk4, vs my other cars, but the main ways it seems to get its ridiculous mpgs are:

a) Regen braking

b) Running the engine at its most efficient RPM as much as possible

The regen braking is self explanatory - Energy that would be wasted at braking is used to charge the Battery.

The second is new to me, but interesting: Supposedly, the average Otto-cycle petrol engine is peak 30% efficient, but it hardly ever runs at that 30% efficiency range so the average efficiency is even worse.

By comparison, my Mk4 almost rabidly tries to keep the engine at ~2000rpm - I assume this is where the Dynamic Force's magic 41% efficiency zone is. Now, this might seem a bit daft - Say I'm moving at 8mph in traffic, but the car is doing 2000rpm - You don't need 2000rpm to move at 8mph so surely that's wasting fuel? But the car is most efficient at 2000rpm so it really wants to run at that speed... so the hybrid has a trick! It can take the small portion of that energy needed to propel the car at 8mph, and capture the otherwise-wasted excess energy and dump it into the traction Battery! That way it can extract 41% of the energy from the petrol almost all the time!

A non-hybrid ICE vehicle can't do that - It's locked to the speed and gear, so while you could run it at 2000rpm optimal efficiency at 8mph, the amount of energy extracted is far more than the car needs to move at 8mph and unlike the hybrid it has nowhere to put it, so it just gets wasted as heat and noise. More likely you'd go to 2nd gear and run the engine at a lower rpm - Less heat, less noise, but also a lower efficiency so although you're using less fuel than in 1st, you're not extracting as much energy out of the fuel as you could be, so more is used than it would otherwise...

This is all theoretical anyway, I don't know how the heck it's giving me such high MPGs. I tend to accelerate quite... briskly up to the speed limit so I'm sure it's not running in that 41% efficiency zone as much as it could be  

But all that is one of the reasons I regret the demise of diesel - My Mk1 D4D could get close to my Mk4's efficiency without all these tricks - Imagine if it had access to those tricks too! The idea of successfully applying this sort of optimization and energy recovery to it would yield even more ridiculous mpg results I'm sure, but it is a lot harder to do with diesel engines - They don't put out as much waste heat as petrol, yet want to be hot to be efficient, but hybrids tend to run very cool as they don't run the engine all the time so the diesel lump rarely gets hot enough to run efficiently... This is a spiralling issue nobody has figured out a practical way to address yet - We've seen some attempts by the french companies but those diesel-hybrids have been... bad. Inefficient, slow, unreliable. But they have the potential to be so much better, just as the barely-better than a normal car Prius Mk2, has evolved into this hooning-around-and-still-getting-75+mpg insanity that is the Mk4! 

Then again, maybe a petrol engine is just a better counterpart for the hybrid system since it heats up much faster so it can reach its max efficiency state faster - even if it's max efficiency is lower than a diesel's max efficiency, at least it can get there without needing to be run for half an hour!

 

[CPN]

2 hours ago, Cyker said:

No, the main strength of Toyota's hybrids is they are extremely good at recovering energy that would otherwise be wasted, and there is a lot of it!

Indeed, and that's mostly (I think) where Toyota put the thrust ('scuse the pun!) of its software engineers and its electronics to good use...

2 hours ago, Cyker said:

The second is new to me, but interesting: Supposedly, the average Otto-cycle petrol engine is peak 30% efficient, but it hardly ever runs at that 30% efficiency range so the average efficiency is even worse.

What is even more interesting is the way that Toyota maximises the efficiency of the ICE by switching from Otto to Atkinson and back again on-the-fly to try and keep the ICE's efficiency as high as possible for a wide variety of driving conditions...

2 hours ago, Cyker said:

That way it can extract 41% of the energy from the petrol almost all the time!

...and that's the clever trick that the new TNGA platform has up its sleeve...

2 hours ago, Cyker said:

Then again, maybe a petrol engine is just a better counterpart for the hybrid system since it heats up much faster so it can reach its max efficiency state faster - even if it's max efficiency is lower than a diesel's max efficiency, at least it can get there without needing to be run for half an hour!

...and thereby hangs the petrol over diesel "forté" and probably one of the keys to Toyota's success with its hybrid platform variants...

[TonyHSD]

Just for reference 1.8 hybrid in Prius or Corolla has 38.9% thermal efficiency vs  2.0 hybrid 40% efficiency, not only dynamic force engines are great but 1.8 too even the gen 3 one from 2010 and this is where a big difference has happened technically with Toyota hybrids power trains for both ice engines and transmission. The majority of people who classes Toyota together with other hybrids as not efficient or cleaner solutions are away from the truth. Toyota hybrids are different and obviously the best of all ice cars, I don’t know why other manufacturers didn’t follow and copy that drive train, then things might have been different but all tried to add some sort of electrification to their existing power trains with end results nothing but disaster and reliability lower than actually what those had been originally with only one power source. VW Jetta hybrid for example, Mercedes’ E300h, Audi Q7, everything.
On the other side with mild hybrids instead of a standard starter motor there is a small 48v e motor mounted next to the clutch pack who job is to start the ice and only in ideal conditions can eventually propel the car or add some extra boost to the power train, the only benefit is that you have some sort of regenerative braking and less heat and wear to the brakes, still something but nowhere near as Toyota. The diesel problem., it is only one - diesel burning it’s a dirty process, whatever you try to minimise that it will remain dirty therefore it should be used only in specific vehicles where the benefit of been a Diesel engine overcome the pollution effect. , lorries, trains, pick up tracks , anything big. 👍

[yossarian247]

11 hours ago, Cyker said:

 

No, the main strength of Toyota's hybrids is they are extremely good at recovering energy that would otherwise be wasted, and there is a lot of it!

 

 

And that is what the chap that I was discussing/arguing about this with on Facebook couldn't get his head around. Of course a hybrid system neither creates nor destroys energy (as he seemed to think the car manufacturers were claiming), that would be impossible. It simply turns some of the enormous amount of energy normally wasted by a standard internal combustion engine & drivetrain and turns it back into a useful form to propel the car. Because an ICE is inherently so inefficient, a well-designed hybrid setup can quite easily recover enough of this energy to more than cover the energy used in carrying its own weight around and therefore significantly improve overall fuel consumption. He kept coming back to 'but if a hybrid system recovered more energy than it used that would be breaking the first law of thermodynamics', which is both totally misunderstanding what a hybrid does and how the first law applies in this case.

[TonyHSD]

12 minutes ago, yossarian247 said:

And that is what the chap that I was discussing/arguing about this with on Facebook couldn't get his head around. Of course a hybrid system neither creates nor destroys energy (as he seemed to think the car manufacturers were claiming), that would be impossible. It simply turns some of the enormous amount of energy normally wasted by a standard internal combustion engine & drivetrain and turns it back into a useful form to propel the car. Because an ICE is inherently so inefficient, a well-designed hybrid setup can quite easily recover enough of this energy to more than cover the energy used in carrying its own weight around and therefore significantly improve overall fuel consumption. He kept coming back to 'but if a hybrid system recovered more energy than it used that would be breaking the first law of thermodynamics', which is both totally misunderstanding what a hybrid does and how the first law applies in this case.

I would not go into argument with this man or anyone like him 🤣👍

[yossarian247]

Just now, TonyHSD said:

I would not go into argument with this man or anyone like him 🤣👍

Wise words! 

[Stopeter44]

2 hours ago, yossarian247 said:

And that is what the chap that I was discussing/arguing about this with on Facebook couldn't get his head around. Of course a hybrid system neither creates nor destroys energy (as he seemed to think the car manufacturers were claiming), that would be impossible. .... He kept coming back to 'but if a hybrid system recovered more energy than it used that would be breaking the first law of thermodynamics', which is both totally misunderstanding what a hybrid does and how the first law applies in this case.

Talking of head wraps. I fully get the way Toyota has evolved the original Hybrid concept, I read the wikipedia Hybrid Synergy Drive page a number of times. Each time I did, a bit more of the puzzle fell into place in my understanding. 

There's one part of the system that I don't fully understand. I understand the logical concept of the power split device, that is the planetary gear set, but I don't understand, with the MG1, MG2 & ICE connected to it, how the ICE can be stopped. Does it have some kind of freewheel system, akin to the Hub gears on my bicycle ? @TonyHSD in another thread pointed out some videos explaining how, conceptually, the Toyota system worked, but I'm still struggling with the "stopped" ICE in the setup.

Can anybody shed more light on this ?