Aussie motoring journo John Cadogan recent did a video on this subject, summed up by YMMV. It really depends on your driving pattern, where you drive and how long you intend to keep the car.
He also mentioned that it's nigh on impossible to get an accurate cradle-to grave carbon footprint on cars, especially as regards of all the mining, manufacture/assembly and disposal/recycling of parts, especially as it's difficult to check the mix of electricity production and fuel usage of every vehicle, piece of machinery and person responsible.
Note that many people have had serious difficulties owning hybrid vehciles who do low amounts of short-distance driving, because both the 'ICE' regular battery and the hybrid ones regularly go flat (especially the former) because there is little opportunity to charge them up, leading to vastly shorter lifespans.
As I often point out, those who advocate people buying EVs conveniently forget that many people in the aforementioned situation also are either not well off and/or live in homes (flats, terraced houses, etc) that fitting EV chargers is physically impossible, incredibly expensive or prohibitive due to high crime (vandalism) in their area.
In many cases, such cars are parked well away from the property and not in an 'allocated space', often on ordinary streets where there may not be a lamp-post that could take a charger - assuming one wasn't vandalised etc whilst unattended.
As such, for the moment at least, an ICE petrol car is still really the only viable option. Perhaps when EV and replacement battery pack prices come down significantly (noting that a large percentage of this groups will be buying cars in the [2021 prices] the under £5k price bracket (possibly under £2k) and where widespread, standardised and reliable fast-chargers are available can this large group be attracted away from ICE-only.
Standard hybrids and PHEVs are all well and good, but unless they are used as intended, all they are are under-powered, heavy cars dragging dead weight around with more and expensive components to go wrong and to replcae when they do.
To make best use of them, owners also need to keep them for a reasonable amount of time and do a significant amount of mileage - but mainly on roads which a conducive to their supposed green credentials - i.e. not longer trips and/or on motorways, but more urban driving.
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Not all hybrid systems are the same
I found the mild hybrid in a fiesta to have minimal impact where as the hybrid system in the Honda Jazz is very impressive; 80mpg on a run is easily achievable (highest I got was 99mpg but that was with a lot of motorway driving at 68/70mph).
I found the hybrid system in the Suzuki Swift to be slightly better then the fiesta, it was involved more where the Ford system appeared to be no more than a bolt on for emissions purposes.
Haven’t tried a new Toyota Yaris which like the Jazz only comes in a hybrid but the one person I know who owns one says it’s far more economical than the previous Yaris.
Edited by daveyK_UK on 27/10/2021 at 17:56
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A hybrid car has two entire powertrains. I feel that this is not a good use of resources. I would like to know the energy and material input to a hybrid and how it compares with a ICE car. There are some pretty rare and expensive material used in the electric drive systems.
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Not all hybrid systems are the same I found the mild hybrid in a fiesta to have minimal impact where as the hybrid system in the Honda Jazz is very impressive; 80mpg on a run is easily achievable (highest I got was 99mpg but that was with a lot of motorway driving at 68/70mph). I found the hybrid system in the Suzuki Swift to be slightly better then the fiesta, it was involved more where the Ford system appeared to be no more than a bolt on for emissions purposes. Haven’t tried a new Toyota Yaris which like the Jazz only comes in a hybrid but the one person I know who owns one says it’s far more economical than the previous Yaris.
How did a mild hybrid achieve such a high mpg on a (long?) motorway run - the who point of them is that they are designed for urban use, because the batteries offer very small range on their own (mostly under 5 miles and only when driven gently), just for getting off the mark/overtaking where a quick power boost is needed or to power the electrics.
Once they've been depleted in such a fashion, they only get recharged when used for a decent amount of (regenerative) braking, which motorway driving (presumably not stop-start in heavy traffic) in not conducive to. A family member used to own a 2007 Civic with IMA and they did get better mpg, but not anywhere near 99mpg. Was yours the average or the max, which could've been on a downhill section?
I'm wondering if that Jazz was more than just a 'mild' hybrid? What's the eletcric motor only range on it and/or battery capacity? Sounds more like a PHEV capacity.
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A mild hybrid, or self charging hybrid are constantly depleting and charging their batteries. Even with cruise control set at 70mph on the motorway, it’s either using a little ICE power to charge it, or it’s cutting the engine, even momentarily, to maintain speed on descents.
Try driving at a constant speed on anything other than a billiard table smooth, runway type road, your foot will be making constant adjustments to hold the speed steady - every time the cruise backs off the throttle, that’s energy going into the battery.
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Succinctly and clearly explained, mcb. Unfortunately, it won't stop others continuing to think of the regenerative system as a dead weight that the ICE is lugging about...
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Succinctly and clearly explained, mcb. Unfortunately, it won't stop others continuing to think of the regenerative system as a dead weight that the ICE is lugging about...
If that's the case, how exactly is that EXTRA fuel used the charge the hybrid battery up any different to using it to provide motive power? Either way, it ain't free energy to bump UP the mpg on such a run - in fact, quite the opposite, given in addition to the extra fuel being used at all, all the extra components used in the car for charging it and electric motive power is extra weight to carry around over a pure ICE car.
It's actually WORSE than the car not charging it and carry the hubrd battery as dead weight, because there are energy losses (to heat) by the ICE engine charging the hybrid battery, then it being used to power the electric motor.
Go look up the laws of thermodynamics. Hybrids are mainly used to reduce urban pollution via regenerative braking (something that doesn't happen anywhere near as much on motorway only driving) generating the electricity that significantly increases the mpg over a pure ICE car, where the energy in braking is just vented as waste heat.
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Most on here will know that an ICE is not equally thermally efficient at all points in its rpm/load curves. They tend to have ’sweet spots’ where the brake specific fuel consumption will be at its lowest.
The advantage of a hybrid (I’m thinking Toyota specifically here) is that as the ICE is not directly connected to the wheels, its rpm is independent of the road speed. The ICE can be run at it's optimum config with some of the energy driving the vehicle, and the excess being bled back to the battery.
The hybrid set up is designed to extract as many joules as possible from a given quantity of fuel. The fact that the engine runs at higher load is inconsequential if it runs for a shorter period of time and creates more useful energy when it does so.
We have owned a CHR hybrid for about 8 months now. We’ve found that its long term fuel economy average is about 25% higher than the conventional ICE car it replaced, despite the CHR being heavier by some 250Kg (It was a Suzuki S-Cross in case anyone's wondering).
On some of the motorway trips I’ve undertaken in it, I have managed mid 60’s at a steady 70mph, I reckon slowing down a bit to 60mph that over 70mpg would be achievable. I would consider this to be perfectly adequate for something that’s ‘no good for motorways’.
Edited by moward on 29/10/2021 at 15:48
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Most on here will know that an ICE is not equally thermally efficient at all points in its rpm/load curves. They tend to have ’sweet spots’ where the brake specific fuel consumption will be at its lowest.
The advantage of a hybrid (I’m thinking Toyota specifically here) is that as the ICE is not directly connected to the wheels, its rpm is independent of the road speed. The ICE can be run at it's optimum config with some of the energy driving the vehicle, and the excess being bled back to the battery.
The hybrid set up is designed to extract as many joules as possible from a given quantity of fuel. The fact that the engine runs at higher load is inconsequential if it runs for a shorter period of time and creates more useful energy when it does so.
We have owned a CHR hybrid for about 8 months now. We’ve found that its long term fuel economy average is about 25% higher than the conventional ICE car it replaced, despite the CHR being heavier by some 250Kg (It was a Suzuki S-Cross in case anyone's wondering).
On some of the motorway trips I’ve undertaken in it, I have managed mid 60’s at a steady 70mph, I reckon slowing down a bit to 60mph that over 70mpg would be achievable. I would consider this to be perfectly adequate for something that’s ‘no good for motorways’.
Most trip computers aren't that accurate on mpg. Besides, quoting what appears to be peak mpg may not give a true representation. My 15yo Mazda3 1.6 petrol can manage a peak of about 48mpg by the same method when I go on holiday down the M4/M5, which is not that far off the mid 50s my BIL's old Honda Civic (06) hybrid (1.3 IMA) achieved across similar trips, though my car was more spritely.
I think it often dependes upon how the driver drives the car as much as the engine and hybrid tech itself - I think that hybrids are designed to be driven gently, which means less overtaking, slower speeds generally and pulling away more gently too.
Note that in your case, the engine tech (and possibly the aerodynamics) of your previous car may well have been quite a bit inferior to that of your current one, so it may not be such a fair comparison. Many current day ICE petrol cars of that size can easily reach 50mpg on the motorway, and quite a bit more for diesels.
Was your Suzuki an automatic like the CH-R, and was it a 4x4? The older-tech (I think) TC auto in the former (like it would in my car) saps a lot more power (and thus fuel) than a DCT or CVT, as it would it (and by quite a bit) if it was a 4x4 version. Not meaning to imply anything, just that you might have overlooked some things in your comparison.
My own car's latest 'equivalent' (which is about 150kg heavier and a bit quicker) has a real mpg figure (I'm quoting the gen-3 car as it uses essentially the same SA-G engine with a bit of hybrid tech added for the gen-4) of about 45mpg, but I could likely get around the manufacturer's quoted average figure - possibly even higher (I can get 40-41mpg ave out my gen-1 car) because I'm a light-footed driver (the same happened with my old mid-90sMicra).
Perhaps you car is fine for 'steady Eddie' on the motorway, but even when I use them out of the school holiday season (and out of the rush hour), I rarely can stick at one speed for long due to traffic that you have keep overtaking to make progress. I've heard many people confirm this where they think that car's cruise control isn't as useful as they had hoped. I know quite a few people with hybrid cars that have been disappointed with the fuel effeciency if they drive (in their eyes) 'normally'.
Perhaps I should buy a proper hybrid, given my driving style? Anyone got £30k to spare? :-)
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The mid 60’s I achieved was an average achieved over a roughly 200 mile trip on a scorching hot day with copious use of the air con, I’m sure I could have done better in more ordinary circumstances. I know the in dash displays can be somewhat inaccurate by a few % each way so I treat them as informative only.
Our Suzuki was manual, a 1.6 petrol SZ-T with FWD and the comparison I made is like for like. It averaged about 38mpg all in on a quite hilly commute, which I thought pretty decent to be honest. The CHR averages a little over 50 on the same route over the course of a tank. There’s no question it uses less fuel, my petrol receipts will back that up ;-)
We rarely do motorway journeys, so aerodynamics probably didn’t really come into play much when comparing the two, the CHR is probably a more aero friendly shape vs the boxy Suzuki but the fastest road on my Mrs commute is 40mph.
I know quite a few people with hybrid cars that have been disappointed with the fuel effeciency if they drive (in their eyes) 'normally'.
We drive pretty normally and find it fine but neither of us are aggressive drivers. As has been mentioned on this thread, taking advantage of the decelerative period is key to getting the max potential out of it. Anticipation and gently slowing down towards a red light gives the battery time to soak up as much energy as it can, (the rate at which the battery can accept charge is limited, brake too hard and the hydraulic brakes kick in and waste all that kinetic energy as heat).
Our reason for buying the hybrid was not motived by money, the fact that it does cost less to run is just icing on the cake. It was simply because we liked how it drove. Quiet and refined with a surprising amount of pep from standstill and no gears, clutches, jerks or stutters. It’s probably the smoothest driving car I’ve ever driven.
Lastly as an engineer, I take a great interest in the technical side of things and how they work (inner geek). IMO the Toyota HSD is a work of genius, an automatic transmission with very few moving parts and very little to wear out. The HSD is mechanically very simple, especially compared to more conventional autos such as a torque converter or DSG, and yet has the potential to return better efficiency than any of them. The clever (read complex) bit is in the control logic that oversees it. The video linked below by Prof. John Kelly of the Weber State University shows a teardown of one of these transmissions and a brief overview of how it works.
2016 - 2022 Prius, Prius Prime Transaxle - P610 Deep Dive (P710, P810 Similar) - YouTube
Perhaps I should buy a proper hybrid, given my driving style? Anyone got £30k to spare? :-)
I think you should try one, never know, you might even like it ;-P
On a final tongue in cheek note, for anyone that thinks a hybrid car is ‘complex’, it is nothing compared to a typical passenger aircraft. Most have no problem boarding these so they can’t be too put off by complexity :-P
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A mild hybrid, or self charging hybrid are constantly depleting and charging their batteries. Even with cruise control set at 70mph on the motorway, it’s either using a little ICE power to charge it, or it’s cutting the engine, even momentarily, to maintain speed on descents. Try driving at a constant speed on anything other than a billiard table smooth, runway type road, your foot will be making constant adjustments to hold the speed steady - every time the cruise backs off the throttle, that’s energy going into the battery.
But a hybrid consistently obtains much better economy than an ICE car. You can put a lot of this down to the Atkinson cycle Toyota use and I refuse to accept that regenerative braking contributes more than a microscopic addition. So how do they do it, when they're lugging all that extra weight?
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You’re telling me that it’s mostly down to the Atkinson cycle engine, but then asking how it produces better economy.
Yes, the Atkinson ICE contributes, but check the figure I posted above - in tests, a Prius was tailpipe emission free - running on its battery, or coasting/regenerating for 62.5% of journey distance.
If you haven’t driven one, they usually have a display showing power flows between ICE, battery and wheels.
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You’re telling me that it’s mostly down to the Atkinson cycle engine, but then asking how it produces better economy. Yes, the Atkinson ICE contributes, but check the figure I posted above - in tests, a Prius was tailpipe emission free - running on its battery, or coasting/regenerating for 62.5% of journey distance. If you haven’t driven one, they usually have a display showing power flows between ICE, battery and wheels.
What happens on the return journey when it went back up the hill? :-)
Bear in mind car companies and their 'academic' helpers have been known to tell fibs in the past.
Coasting is only possible on downhill sections, and regenning is only possible when braking, which means that journey would be downhill and/or likely urban.
I'd like to see a Prius with just an Atkinson cycle ICE engine with no hybrid system and compare it to the hybrid across a variety of different journey patterns.
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‘Coasting is only possible on downhill sections, and regenning is only possible when braking, which means that journey would be downhill and/or likely urban.
I'd like to see a Prius with just an Atkinson cycle ICE engine with no hybrid system and compare it to the hybrid across a variety of different journey patterns.’
Coasting happens very frequently, even on ‘level’ roads. Every undulation reduces the load on an engine, and during that brief period of time a hybrid will, momentarily, regen the battery. Just because the speedo and rev counter are pointing at the same part of their scales, it doesn’t mean the engine/motor is under the same load. It’s constantly fluctuating, and the control unit will quickly decide the most economic mode.
As mentioned elsewhere, regeneration takes place whenever the car isn’t being powered, and is in no way dependent on the brakes being applied. Regeneration can be increased by lightly pressing the brake, and hydraulic braking takes over after a certain requested rate of deceleration.
An Atkinson engine, running solo, wouldn’t be a pleasant thing to drive without using it to support the electrical propulsion motor(s). They produce efficiency at the expense of power density, so would be pretty slow and noisy. That’s why no one uses them like this.
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‘Coasting is only possible on downhill sections, and regenning is only possible when braking, which means that journey would be downhill and/or likely urban. I'd like to see a Prius with just an Atkinson cycle ICE engine with no hybrid system and compare it to the hybrid across a variety of different journey patterns.’ Coasting happens very frequently, even on ‘level’ roads. Every undulation reduces the load on an engine, and during that brief period of time a hybrid will, momentarily, regen the battery. Just because the speedo and rev counter are pointing at the same part of their scales, it doesn’t mean the engine/motor is under the same load. It’s constantly fluctuating, and the control unit will quickly decide the most economic mode. As mentioned elsewhere, regeneration takes place whenever the car isn’t being powered, and is in no way dependent on the brakes being applied. Regeneration can be increased by lightly pressing the brake, and hydraulic braking takes over after a certain requested rate of deceleration. An Atkinson engine, running solo, wouldn’t be a pleasant thing to drive without using it to support the electrical propulsion motor(s). They produce efficiency at the expense of power density, so would be pretty slow and noisy. That’s why no one uses them like this.
Doesn't/didn't one of the BMW i-somethings (i8?) use a high-efficiency petrol engine (a range-extender, perhaps?) to only charge the EV-part battery, which itself was the only motive power to the wheels?
To me, that sounds like a far better system, because it would involve a much smaller, lighter petrol (or diesel) engine. Perhaps it was used this system because it produced the most torque for outright performance (load-lugging could be another task, as used on diesel-electric trains for decades).
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A very mild hybrid incapable of actually moving the car under elecric power alone is still a hybrid. If capable of moving the car at low speed in town for 2 or 3 miles there could be some clear benefit.
Pure mild hybrids seem more in common to start stop technology - a way for manufacturers to shout their green credentials and making a small difference to economy under test conditions.
Whether the small amount of energy recovered through braking justifies the additional weight and complexity must be debatable. They carry a low cost premium because (bluntly) they don't do very much!
Hmm,
Adding a mild hybrid system takes the average mpg of an otherwise identical Suzuki Ignis from 50.9 to 59.6mpg, representing a 17% improvement in efficiency (under identical testing conditions).
Paul 1963's Suzuki Vitara mild hybrid is averaging 52mpg. Coincidentally, that is an improvement in efficiency of around 17.5% over what John F is getting from his Peugeot 2008 (non hybrid, mild or otherwise), a similar size and type of car.
Not bad for something you claim doesn't do very much...............
At least with mild hybrids, full hybrids, battery electric cars and ICE cars you have a pretty good idea what you'll get. The car does it's thing and gives you a certain level of emissions. The only exception is the plug-in hybrid. Plug-in hybrids emissions depends entirely on how much, or even whether, they are charged. They are capable of almost elecric car low emissions ir considerably worse than ICE cars solely dependent on how much they are charged. On that basis, why they get such low company car tax is beyond me.
You seem to be under the impression that a plug in hybrid only charges if it is plugged in. Not so, a PHEV can also charge itself in the same way as a self charge hybrid does.
Edited by badbusdriver on 27/10/2021 at 18:12
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Nicely put BBD, not sure Terry fully understands? need to add whilst Johns pug is a 1.2 the Vitara is a 1.4 ( both turbo of course)
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Nicely put BBD, not sure Terry fully understands? need to add whilst Johns pug is a 1.2 the Vitara is a 1.4 ( both turbo of course)
Yes, clearly there could be plenty more to the difference than simply a mild hybrid system, not least the presence of the t/c auto in John F's 2008. But I did find it interesting that the difference was pretty much the same as that between Ignis and Ignis mild hybrid!.
As it happens, thanks to the (Suzuki) power outputs mysteriously reducing with the addition of the mild hybrid system (1.2 Dualjet down from 89-83bhp, 1.4 Boosterjet down from 138-129bhp) the power of your Vitara is as near as dammit the same as John F's car (130bhp).
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The Toyota system is well proven and familiar and certainly works brilliantly around town.
Forget all that start/stop rubbish - for heavy traffic town driving the hybrids work very well and the engine can be off a lot of the time.
If you are hacking up and down motorways at 85mph all day they are not such a good idea.
The other thing is hybrids allow the ICE to run on the Atkinson cycle which makes a difference.
I'm less convinced about "mild" hybrids which is most cases add little and seem something of a marketing effort to string a few more years out of an existing drivetrain design.
Edited by pd on 28/10/2021 at 13:58
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But a hybrid consistently obtains much better economy than an ICE car. You can put a lot of this down to the Atkinson cycle Toyota use and I refuse to accept that regenerative braking contributes more than a microscopic addition. So how do they do it, when they're lugging all that extra weight?
First, a self charge hybrid doesn't have that big a battery, so "all that weight" doesn't actually add up to very much. The figures in the review for the Toyota Auris in this website say that the 1.8 hybrid is only 40kg heavier than the 1.2t CVT(*). Second, within reason, extra weight is going to have virtually no effect at cruising speed, only accelerating.
Regenerative braking is one of the main ways in which a self charge hybrid charges, but how much that amounts to will depend on how often you brake. If you brake a lot, it will contribute a lot, if you don't it won't.
(*) Earlier in the thread, using the same source (this website) I posted that the difference between hybrid and non hybrid (CVT) on the previous shape Yaris is only 25kg.
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If we’re being spectacularly pedantic, it should be regenerative deceleration as there is no link betwixt the brakes and the battery.
By braking, a driver is shortening the number of wheel revolutions after stepping off the accelerator, therefore cutting the amount of regeneration that can take place.
By anticipating early, and coasting for greater distance without braking, the more effective the regeneration will be.
There will be some degree of increasing the regeneration via the brake pedal, but it’s sometimes difficult to distinguish between the enhanced regeneration slowing the car and the hydraulic brakes coming into play, which will mean wasted energy in the form of heat.
Edited by mcb100 on 28/10/2021 at 20:35
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Regenerative braking is one of the main ways in which a self charge hybrid charges, but how much that amounts to will depend on how often you brake. If you brake a lot, it will contribute a lot, if you don't it won't.
Also, some hybrids, such as my Jazz, have a 'B' option on the transmission lever which is like 'D' or Drive, but gives you increased regenerative braking, even when you don't have your foot on the brake pedal, so it acts a bit like engine braking on a conventional ICE car.
This can rapidly charge the HV battery on even a fairly modest hill. In fact today I was on the 6th floor of a multi-storey car park. I put the drive in 'B' and by the time I got to street level, the battery had gone from about 25% to 75% charged.
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If we’re being spectacularly pedantic, it should be regenerative deceleration as there is no link betwixt the brakes and the battery.
Fair do's!
;-)
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have a 'B' option on the transmission
Many people haven't got a clue what it is for and hence never used.
Another of my peeve with hybrids that except some expensive models, they don't have the manual gear shift option (with +/-) - either as flappy pedals or on shifter as S mode.
This drives away some people who consider hybrids (which mostly have CVTs) as boring to drive.
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Not sure of anyone else’s hybrid systems, but the Toyota system doesn’t have a CVT. Not a belt or chain in sight.
It uses one petrol engine, two motor/generators and a very clever power split device to send power to the wheels from either just ICE, just a motor, or a combination of both. Granted, it sounds like it has a CVT, but look as hard as you like and you won’t find a gearbox.
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Not sure of anyone else’s hybrid systems, but the Toyota system doesn’t have a CVT. Not a belt or chain in sight. It uses one petrol engine, two motor/generators and a very clever power split device to send power to the wheels from either just ICE, just a motor, or a combination of both. Granted, it sounds like it has a CVT, but look as hard as you like and you won’t find a gearbox.
Nevertheless, Toyota describes HSD-equipped vehicles as having an e-CVT (electronic continuously variable transmission) and HSD does require a mechanical planetary gear set in the transaxle.
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have a 'B' option on the transmission
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Many people haven't got a clue what it is for and hence never used.
Only if they choose not to. Granted, if they received the car new during the stages of the pandemic where car dealerships were only open up to a point, the handover would have consisted of receiving the key and being told to get in touch with any questions. Otherwise they would be told about any such control, though they may have chosen not to have listened(!).
Another of my peeve with hybrids that except some expensive models, they don't have the manual gear shift option (with +/-) - either as flappy pedals or on shifter as S mode.
That isn't really the case, whether or not they have a manual shift option will depend on the type of transmission. Toyota/Lexus hybrids use epicyclic transmission which don't. All Hyundai or Kia hybrids use a DCT gearbox and hence can be shifted manually like any other DCT.
This drives away some people who consider hybrids (which mostly have CVTs) as boring to drive.
I don't agree with this at all. The vast majority of people who buy cars with two pedals put in drive when they go anywhere and leave it there till they either stop or need to go backwards, regardless of whether hybrid or otherwise.
Edited by badbusdriver on 29/10/2021 at 18:15
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