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CVT gearbox...is there a 'knack' to driving one?


Sloth
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8 hours ago, Sloth said:

Hi, I'm expecting my new ES300h F Sport (Takumi pack) around mid-late June. I had test driven but only for a few miles and not for any length of time or distance.

I'm really looking forward to it but having now driven a courtesy car (UX250h F Sport with Takumi pack) for a few weeks whilst waiting I do have some slight concerns about the CVT gearbox...

This was posted 8 hours ago. I'll assume the problem has resolved itself :smile:

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8 minutes ago, royoftherovers said:

And you didn`t warn him Roger? tut,tut.

He is not the kind of person you can “advise”, not only that he has just ordered the same again, and will then sell the old one on, probably at auction .....tut tut.

Is it the Rioja that is making you ‘tut’ John

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Good try Roger. This evening it was a white Burgundy I picked up in France on my way down. I could not find the usual Chablis !

Oven cooked vegetables with white Merluza (Hake), followed by Local Cherries and Yoghurt.

Oh to be retired!!.

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3 hours ago, First_Lexus said:

Funny, I detest the DSG gearboxes when I've owned them and driven them since (VAG) finding them to be hesitant, jerky and often 'hunting' for a gear. Often pulling out at junctions and roundabouts was nerve racking to say the least! There wasn't a fault either as mine did this both with the original box and the replacement - the original exploded at 40k miles. Oh, did I mention the well known reliability issues? 😂

Even What Car? have (finally) admitted they aren't the best, criticising the latest Audi DSG in the Q3 for exactly what I was finding for 3 years.

Anyway, I've had CVT gearboxes since 2004 and actually try to seek out cars with them - one of the reasons I went Lexus in fact. Drive smoothly, and accelerate gradually, and they are so much more refined than other autos imho. I will admit they probably aren't for those who drive aggressively, but then again the DSG was a nightmare for that too...

 

Well it’s not a Lexus `I guess 🙄

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16 hours ago, royoftherovers said:

Sloth (surely you must have a Christian name I can warm to?), many thanks for providing the background against which your purchase was made.

I understand where you are coming from, but having spent 42 years of my life chasing my tail, my experience tells me that researching any decision which is capable of having consequences, is not farting around. It is a pre-requisite to informed decision making.

I am fortunate in that my engine is a 3.5 litre V6 and it just glides.Gears are irrelevant as they do not exist and progress, rather than acceleration, is progressive and linear.The car continues at speed even when the pedal is lifted as the electric motor comes into play.

I am sure that your Lexus engine has similar characteristics and that if you can invest the time to harness its character, quality and unique abilities, you will begin to appreciate what a superb vehicle it is.

I look forward to reading your future contributions as to how you are getting on with it.

 

Regards

John. 

Good morning John, my name is Neil 🤝

I agree that given time I will get used to it and have been making a concerted effort the last 48 hours to get a better 'feel' for the CVT in the UX courtesy car. I'm hoping my ES with it's slightly larger 2.5 engine, sadly not a 3.5 V6 (company car policy and my BIK drivers will not allow for that) will be a different and hopefully less revvy experience. I am assured of this by the Lexus salesman, who of course would never lie or mislead due to the strict and sacred salesman's code of conduct.......:ermm:

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If it's anything like my RC300h , you'll love it!

Only ~5 weeks till my new face-lift model gets delivered (tracker suggests it's off the coast of Sri Lanker currently) can't wait :yahoo:

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1 hour ago, Sloth said:

Good morning John, my name is Neil 🤝

I agree that given time I will get used to it and have been making a concerted effort the last 48 hours to get a better 'feel' for the CVT in the UX courtesy car. I'm hoping my ES with it's slightly larger 2.5 engine, sadly not a 3.5 V6 (company car policy and my BIK drivers will not allow for that) will be a different and hopefully less revvy experience. I am assured of this by the Lexus salesman, who of course would never lie or mislead due to the strict and sacred salesman's code of conduct.......:ermm:

Thanks Neil, much appreciated.I have never relied on a Salesman unless he has put it in writing!

Enjoy your ES. It will never respond like other cars you have driven, so modify your approach to driving and relish the World that is Lexus.

Please keep us all updated with your experiences.

Regards

John 

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1 hour ago, NemesisUK said:

If it's anything like my RC300h , you'll love it!

Only ~5 weeks till my new face-lift model gets delivered (tracker suggests it's off the coast of Sri Lanker currently) can't wait :yahoo:

Sri Lanka..........just in case you are thinking of plotting a route Peter !

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9 minutes ago, royoftherovers said:

Sri Lanka..........just in case you are thinking of plotting a route Peter !

Damn it!! I corrected that 3 times and still got it wrong :blush:

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9 minutes ago, NemesisUK said:

Damn it!! I corrected that 3 times and still got it wrong :blush:

Apparently my ES is also on a ship somewhere so perhaps they're on the same one? Having said that mine's been on a ship so long that I suspect it's being paddled by hand the wrong way around the globe!

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3 minutes ago, Sloth said:

Apparently my ES is also on a ship somewhere so perhaps they're on the same one? Having said that mine's been on a ship so long that I suspect it's being paddled by hand the wrong way around the globe!

Get the ship name from your dealer and plug it into this website

https://www.vesselfinder.com/?imo=9293624

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Crikey! I've just had a look at that website Peter and it's a miracle that anyone ever gets lost at sea with that much shipping!!!

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Indeed - I've been using that to track the ships carrying Teslas to europe - my model 3 should be here in July. 

Seems like the thread has moved on, but what you described is the characteristic of the hybrid drivetrain. It puts the engine into the most thermally efficient place it can for any given demand. You must let go some of what you "know" about cars - for example, the hybrids idle fast (1000rpm minimum idle on our GS). At 1000rpm a lot more of the fuel is converted to motion than at 600rpm, and the Battery provides a place to store that energy to actually make use of, instead of being wasted like a regular car at idle. At speed, the thermal efficiency depends on load; this graph (for a 2010 prius, but the principle is the same) explains the behaviour:

Engine-BSFC-map-of-the-Toyota-2RZ-engine

Overall I find that the eCVT driving characteristics are very good - not the best (Pure EV fixed reduction gear is better - no lag, rubber-banding or noise at all, but very good. First_Lexus and I are in agreement regarding VAG DSG gearboxes as woeful (they're great if you're driving the car hard and using the paddles - very smooth and quick. They're hopeless for driving around as an actual Automatic, because they are slow to do a double-downshift and can not provide any slip to mitigate off-boost (eg pulling out of a t-junction) because it would roast the clutch in short order). The eCVT is mechanically simple, gives linear pull as the vehicle accelerates (much more like an EV) and allows for long gearing (our GS will drop to 1500rpm at any motorway cruise speed - according to a youtube autobahn video, this holds true to 100mph or more). 

As for noise... Yes, acceleration does give you a period of a few seconds of constant noise, rather than the variable noise of an ICE with a regular gearbox. It's not like it sits there at 6000rpm the whole way down the motorway or anything, and I don't find the noise behaviour to be more objectionable than eg a 4 cylinder diesel automatic (which as observed elsewhere in this thread will produce plenty of noise when it (eventually) kicks down.

I will take issue with one comment earlier in the thread - that this is the "transmission of the future". It's not. It was... 15 years ago in the Prius. Now it's a mature technology that is going to decline along with the sales of ICE vehicles. Single-speed reduction transmissions will become the default, and eventually maybe direct-drive will be the thing. Those are the "transmissions" of the future. 

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59 minutes ago, i-s said:

I will take issue with one comment earlier in the thread - that this is the "transmission of the future". It's not. It was... 15 years ago in the Prius. Now it's a mature technology that is going to decline along with the sales of ICE vehicles. Single-speed reduction transmissions will become the default, and eventually maybe direct-drive will be the thing. Those are the "transmissions" of the future. 

That was my comment and I would agree with you. The "transmission of the future" was really meant as an observation from my perspective, coming from the traditional autoboxes 

Your comment about lag and 'rubber-banding' is at odds with my experience with the e-CVT in my RC. There is no perceptible lag and definitely no rubber-banding. There are no bands in the e-CVT (I remember the old DAF-Matic!) and no chain drive as in the Prius?

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Nemesis - compared to a conventional automatic on a turbo engine I agree that lag isn't significant. However, compared to the immediacy of an EV drivetrain, it's still there.  By "rubber-banding" I mean that there is  still a change of torque at the wheels for a constant throttle - ie if you go from very light throttle to 1/2 throttle, the car will begin to accelerate immediately, but once the revs have built (within 1/2 second or so) the acceleration has increased. It feels like the car is catching up to the throttle. It contrasts again to the EV throttle response where the torque alters instaneously with the pedal position and as soon as you stop moving the pedal there is no further change to the torque, but again it's nothing that conventional automatics don't do. I'm not saying it's worse than conventional autos in these respects - it isn't. 

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Hopefully your fears about CVT boxes have diminished somewhat.  The video posted by Herbie showing how the Prius gearbox works simply shows how it all works.

Yes the engine will rev if you "floor it", but in every day use, the revs lift a bit then fall back, I even had the engine revs drop whilst accelerating very hard up a very steep hill to overtake a group of cyclists, it does feel most odd, you need to remember that the electric motor speed is tied to the road speed, all the revs from the engine are doing is adding to the electric motor as you are asking for a lot of acceleration.  When cruising along a motorway you will often see that your petrol engine may only be doing 1200rpm, the system varies the speed to optimise the efficiency depending on the current conditions, i.e up/down hill etc.

If you have a relaxed style of driving, you will find it even more relaxing with an eCVT.

Vince

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33 minutes ago, Vince Donald said:

Hopefully your fears about CVT boxes have diminished somewhat.  The video posted by Herbie showing how the Prius gearbox works simply shows how it all works.

Yes the engine will rev if you "floor it", but in every day use, the revs lift a bit then fall back, I even had the engine revs drop whilst accelerating very hard up a very steep hill to overtake a group of cyclists, it does feel most odd, you need to remember that the electric motor speed is tied to the road speed, all the revs from the engine are doing is adding to the electric motor as you are asking for a lot of acceleration.  When cruising along a motorway you will often see that your petrol engine may only be doing 1200rpm, the system varies the speed to optimise the efficiency depending on the current conditions, i.e up/down hill etc.

If you have a relaxed style of driving, you will find it even more relaxing with an eCVT.

Vince

Hi, yes I am somewhat reassured although I still find it strange when the revs shoot up for sustained periods of time.

A few posts above i-s stated 'Yes, acceleration does give you a period of a few seconds of constant noise, rather than the variable noise of an ICE with a regular gearbox' but so far my experience is for far longer than just a few short seconds, it goes on until I relax on the throttle most times.

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28 minutes ago, Sloth said:

Hi, yes I am somewhat reassured although I still find it strange when the revs shoot up for sustained periods of time.

A few posts above i-s stated 'Yes, acceleration does give you a period of a few seconds of constant noise, rather than the variable noise of an ICE with a regular gearbox' but so far my experience is for far longer than just a few short seconds, it goes on until I relax on the throttle most times.

I'm not sure how this is that much different to a traditional autobox - with a traditional autobox if you mash throttle, especially into kickdown, the box swaps a few cogs to a low ratio, the engine revs rise then quickly reach peak torque and then stay high until you ease off - the only difference is that as the cogs in the conventional autobox swap up you have the slight drop in revs of perhaps 1.5k - 2k revs until they build again and another gear swap takes place. The e-cvt simply doesn't have that sawtooth 2k rev cycle but the engine maintains revs at max efficiency until you back off - with the conventional autobox or e-cvt full throttle it's still basically lots of revs and accompanying engine noise... Yes, it is a bit different with the e-cvt - that doesn't make one right or wrong though - remember the Williams F1 car that had a cvt fitted - why - because by holding the engine at peak efficiency the car was quicker than with a conventional gear box. The FIA immediately banned cvts when it was clear it was quicker before it even raced - although there is also another point of view that it was banned because it didn't have the "noise" of a conventional drive train. If one is wedded to that rise and fall in engine revs as the gearbox (less efficiently) moves the car forward an e-cvt will never be the right choice. However, if one has an open mind to change and understands the many benefits the e-cvt delivers over a conventional gearbox in normal day-to-day use one can move forward with the technology. My best advice (having lived with mine for 2.5 years) it to not be concerned and just use the car - the mind remaps to the way the car drives and sounds after a couple of months and unless your daily commute involves flooring the throttle at every opportunity and you really miss that rise and fall of revs and all the gear swapping, the benefits of e-cvt (IMHO) are many compared to any perceived loss.

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22 minutes ago, wharfhouse said:

I'm not sure how this is that much different to a traditional autobox - with a traditional autobox if you mash throttle, especially into kickdown, the box swaps a few cogs to a low ratio, the engine revs rise then quickly reach peak torque and then stay high until you ease off - the only difference is that as the cogs in the conventional autobox swap up you have the slight drop in revs of perhaps 1.5k - 2k revs until they build again and another gear swap takes place. The e-cvt simply doesn't have that sawtooth 2k rev cycle but the engine maintains revs at max efficiency until you back off - with the conventional autobox or e-cvt full throttle it's still basically lots of revs and accompanying engine noise... Yes, it is a bit different with the e-cvt - that doesn't make one right or wrong though - remember the Williams F1 car that had a cvt fitted - why - because by holding the engine at peak efficiency the car was quicker than with a conventional gear box. The FIA immediately banned cvts when it was clear it was quicker before it even raced - although there is also another point of view that it was banned because it didn't have the "noise" of a conventional drive train. If one is wedded to that rise and fall in engine revs as the gearbox (less efficiently) moves the car forward an e-cvt will never be the right choice. However, if one has an open mind to change and understands the many benefits the e-cvt delivers over a conventional gearbox in normal day-to-day use one can move forward with the technology. My best advice (having lived with mine for 2.5 years) it to not be concerned and just use the car - the mind remaps to the way the car drives and sounds after a couple of months and unless your daily commute involves flooring the throttle at every opportunity and you really miss that rise and fall of revs and all the gear swapping, the benefits of e-cvt (IMHO) are many compared to any perceived loss.

That actually helps a lot, well explained, thanks Phil.

It's all about perception I think?

Perhaps it's just a case of insufficient sound proofing that highlights what shouldn't be a problem but just sounds like it is due to it (engine noise) being overly audible. If you couldn't hear the engine you'd not even give it a thought would you?

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16 minutes ago, Sloth said:

That actually helps a lot, well explained, thanks Phil.

It's all about perception I think?

Perhaps it's just a case of insufficient sound proofing that highlights what shouldn't be a problem but just sounds like it is due to it (engine noise) being overly audible. If you couldn't hear the engine you'd not even give it a thought would you?

Yes, I think that there is an element it being "different" - as I said before when I went back to a conventional autobox that was then "different" to what I had become used to with the e-cvt and I found it very alien again even though a few years ago I had numerous cars with conventional autoboxes.

Also, I haven't driven a UX or ES to compare but in the IS the engine isn't all that intrusive and so although you know the revs have risen I don't find it particularly harsh or noisy - I have heard much worse in conventional drive train cars.

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On 5/31/2019 at 10:07 AM, NemesisUK said:

Get the ship name from your dealer and plug it into this website

https://www.vesselfinder.com/?imo=9293624

Well it seems my car is on the same boat as yours!

Trouble is that the position doesn't seem to update and it looks like I need to subscribe (which I won't) in order to get an updated position?

Am I doing it wrong or is that right?

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