Sloth

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

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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.

It's certainly different to what I am used to (Mercedes C300h AMG Line) in that it doesn't have the traditional auto gearbox feel.

My main concern is the high revs when I put my foot down to accelerate/over take and they don't seem to reduce...ever unless I ease off the throttle? In other words it's like the gearbox and myself are playing 'chicken' in who gives up first and it's usually me by easing off the throttle to calm the revs/noise down.

Now as this is a time tested gearbox I'm wondering if there is a 'knack' to driving a CVT fitted car, especially a hybrid.

Do I really need to use the throttle as a means of controlling the gearbox or should I just accept the high and loud revving when accelerating and hope the revs calm down before the engine explodes!!!

I like to accelerate fairly quickly although I am not a boy racer and don't thrash my cars. Does a CVT gearbox doom me to a life of either slow acceleration to keep the engine noise/revs down or to putting up with the revs and noise?

Am I missing a fundamental driving method here?

The UX is a 2.0 l engine whereas the ES is a 2.5l engine so will it behave notably better/differently or will the same problem persist?

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I've come from a traditional auto box (Mercedes AMG) and have to say the e-CVT box in my RC300h is sublime, a real dream!

I really must be missing something because when in 'Normal' drive mode (with no rev counter displayed) I really cannot tell what the revs are doing. If I switch to 'Sport' mode (where the rev counter does display) I can see the engine revs rise and fall, just as they do in traditional autoboxes as the artificially created gears change.

Bottom line is drive the car just as you would any other, the car's systems will keep the revs in the correct range for the load demand and rest assured the engine will not explode!

E-CVT is the transmission of the future, so much more reliable than other autoboxes. Small and relatively simple. No cogs engaging/disengaging, no clutch or brake bands to wear out.

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Thanks for your reply, to be honest it's not the rev display on the tacho that I'm concerned about (I usually stick to the eco-non rev display screen) but rather the notable surge of sustained revs that I hear and feel when I accelerate even modestly but especially if I put my foot down?

I have only used the rev counter display to actually see what the revs were actually doing after I had already noticed the high revs audibly.

Perhaps it's more noticeable with a smaller engine like the 2.0 on the UX, I understand the RC has the same 2.5 engine that my incoming ES will have?

I had another courtesy car for a couple of days which was a RX450h, now that had a 3.5 V6 which was lovely. However although it wasn't as bad or noticeable as the engine was lower revving (and it sounded good anyway), it did still have the notable surge of revs when accelerating in any other way than gently.

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I certainly don't find the engine revving at all intrusive or disconcerting. If there is anything to note I would say no worse than that which one would experience with a traditional autobox downshifting as one accelerates, just without the slight stutter or hesitation as the traditional 'box swaps ratios?

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Hi Peter, I suppose it's not the actual revving itself as that happens on any auto kick down but it's the fact that it doesn't then change up as per a typical auto box, it just revs up and stays there like it's stuck in too low a gear?

It only calms down when I ease off the throttle?

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I can calm it down by just easing off the throttle slightly but should that be necessary?

It may be a case of the engine maintaining the revs until the vehicle speed actually catches up and the speed/rev ration match up? I don't know really.

Rather than sounding like it's kicked down a gear to accelerate it feels like it's kicked down two or more gears and is over revving.

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All as it should be as the computer is keeping the engine at it's most efficient/powerful for the load placed upon it? The ratio changes are all happening seamlessly as the electric motors increase/decrease their contribution.

When you lift off slightly the load demand has dropped and the revs drop to the new most efficient rev range, again the electric motors contributing in the background.

It is a little unnerving initially but after a short while you'll just be enjoying the seamless acceleration.

Wait till you start playing with the transmission S mode and manual 'gear' changes using the paddles, great fun! 

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6 minutes ago, Sloth said:

Rather than sounding like it's kicked down a gear to accelerate it feels like it's kicked down two or more gears and is over revving.

My AMG would drop as many gears as required to give max acceleration, sometimes two or three cogs if I had been pootling around just before mashing the pedal! 

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1 minute ago, NemesisUK said:

My AMG would drop as many gears as required to give max acceleration, sometimes two or three cogs if I had been pootling around just before mashing the pedal! 

Hi Peter, yes but it would also have then changed up to suit as the speed/revs increased whereas the CVT doesn't, it just sits in the high rev band/range.

A little disconcerting as you say as it feels like it's revving too high for too long.

perhaps I'll get used to it.

 

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53 minutes ago, Sloth said:

A little disconcerting as you say as it feels like it's revving too high for too long.

perhaps I'll get used to it.

It isn't and you'll have to - or sell it and get something with a traditional auto box  😉

This may help to explain:

 

 

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I drive my wife’s 1.5 Honda Jazz Sport, cvt, and to be honest I just use the accelerator pedal as required, and let the electronics take care of everything else. It is a different drive, but honestly does not concern me that the engine is high revving  or not, at some point it will adjust.

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3 hours ago, Sloth said:

Do I really need to use the throttle as a means of controlling the gearbox or should I just accept the high and loud revving when accelerating and hope the revs calm down before the engine explodes!!!

I like to accelerate fairly quickly although I am not a boy racer and don't thrash my cars. Does a CVT gearbox doom me to a life of either slow acceleration to keep the engine noise/revs down or to putting up with the revs and noise?

I think what's happening is that the computer is making the best judgement about how to deliver the request you've made through the accelerator. If the accelerator is pushed to the floor your message to the car is to deliver maximum power. This means get the engine to the highest revs possible, where the engine delivers maximum power, But this is limited by the fact that the electric motors can only spin so fast without damage. So the computer adjusts engine speed and gear ratios to achieve the maximum power you're asking for through the accelerator. By contrast, in a conventional car, pressing the accelerator has traditionally meant feed more fuel into the engine. Here the concept is a bit more computer controlled.

This seems to mean that you can only get the engine to maximum revs if the car is going fast enough to accommodate this without damage to the electric motors. 

Here's a video of the IS300h that shows how the engine revs only increase as the car gathers speed. (Thanks Herbie for explaining how to embed video in the forum! Pretty simple!)

 

So if you ease off the throttle, the rate of acceleration will slow. But depending on the circumstances the engine may not reduce revs yet.

However, the good news is that the advice for good fuel consumption is to accelerate fairly hard and then coast. I suppose this is because the engine is at its most efficient at high revs.

The other good news is that when cruising on the motorway (on the IS300h at least) the engine is generally turning at around 1200-1500 rpm whatever the car's speed. This makes long journeys very relaxing.

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You’ll get used to it, just a CVT characteristic. Personally I hate them and would pick a DSG type box any day over either a traditional TC or CVT box.

Having said that the Aisin box (traditional TC) in our old RX300 (and oddly enough in our old Freelander 2) was a gem.

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1 minute ago, Thackeray said:

(Herbie, how do you manage to embed video in the forum, as above? I've never worked out how to do it.)

Simply copy the URL of the Youtube video and then paste directly into your post (don't use the link icon or quote or anything, just a straightforward paste).

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I am more than surprised that anyone can shell out (or have his Company shell out) £46k without driving the car any distance or for any length of time.

I have both a Merc and a Lexus and they require a different set of  driving skills. 

An educational process needs to take place, me thinks.

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18 minutes ago, Thackeray said:

I think what's happening is that the computer is making the best judgement about how to deliver the request you've made through the accelerator. If the accelerator is pushed to the floor your message to the car is to deliver maximum power. This means get the engine to the highest revs possible, where the engine delivers maximum power, But this is limited by the fact that the electric motors can only spin so fast without damage. So the computer adjusts engine speed and gear ratios to achieve the maximum power you're asking for through the accelerator. By contrast, in a conventional car, pressing the accelerator has traditionally meant feed more fuel into the engine. Here the concept is a bit more computer controlled.

This seems to mean that you can only get the engine to maximum revs if the car is going fast enough to accommodate this without damage to the electric motors. 

Here's a video of the IS300h that shows how the engine revs only increase as the car gathers speed. (Thanks Herbie for explaining how to embed video in the forum! Pretty simple!)

 

So if you ease off the throttle, the rate of acceleration will slow. But depending on the circumstances the engine may not reduce revs yet.

However, the good news is that the advice for good fuel consumption is to accelerate fairly hard and then coast. I suppose this is because the engine is at its most efficient at high revs.

The other good news is that when cruising on the motorway (on the IS300h at least) the engine is generally turning at around 1200-1500 rpm whatever the car's speed. This makes long journeys very relaxing.

"how the engine revs only increase as the car gathers speed." ........I appreciate the response and the video but this is not what is happening.

My revs instantly (not only as the speed increases) scream out as soon as I put my foot down (and I don't mean flooring it, just accelerating positively) however the revs do not decrease as the speed increases, only when I ease off the throttle. If I keep my foot on the throttle, neither decreasing or increasing, the revs stay firmly up and do not decrease unless I ease off the throttle.

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25 minutes ago, royoftherovers said:

I am more than surprised that anyone can shell out (or have his Company shell out) £46k without driving the car any distance or for any length of time.

I have both a Merc and a Lexus and they require a different set of  driving skills. 

An educational process needs to take place, me thinks.

John, in an ideal world or where you are buying the car perhaps but in the real world, the business world and one in which I am leasing for 3 years, I simply do not have the time to fart around with extended test drives on various cars. I therefore rely on short test drives, with refreshers as I feel the need and reviews.

I was aware of the CVT from reviews and the short test drives (3 in all over a couple of weeks) however despite it being different to my last standard auto, I made the decision that I could live with it and even get used to it.

My question was if there is a 'knack' to driving the CVT equipped car that may reduce my experience of high revs every time I try to accelerate.

I'm not decrying it or claiming it is not any good, simply asking if there is anything I need to know about driving style/technique regarding it.

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34 minutes ago, Sloth said:

My revs instantly (not only as the speed increases) scream out as soon as I put my foot down

It sounds as if the UX behaves differently from the IS. Maybe a UX owner can confirm this. What I noticed from the video was that, for example, you don't seem to be able to get the engine above 4500 rpm until you hit 50mph. By contrast, from  your experience, the UX seems to be going straight up to maybe 5,000 rpm or more from low speeds (say, 30 mph?). 

The newer electric motors (like on the ES and maybe on the UX) can spin faster without damage. This must mean that the engine can spin faster, too, than on the IS, thus delivering more of its power at lower road speeds. It will be interesting to hear how the ES compares with the UX.

The IS transmission (L210 I think from memory) as well as being a rear-wheel-drive setup has an additional reduction gear, as compared with the Prius transmission in the video above, which allows the car to go faster without making the electric motors spin faster than their maximum design speed. I noticed that the ES transmission doesn't have this reduction gear. Perhaps in a front wheel drive configuration there's less space for extra gear wheels, so the faster spinning newer electric motors get round the problem without the need for a reduction gear. (But am I right in thinking that even so, for these reasons the maximum limited speed for the ES is a bit lower than on the IS?)

So clearly your experience suggests the engine revs faster at low speeds than in the IS. It'll be interesting to hear how the ES behaves and whether it's similar to the UX.

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Hi William, yes I'm also waiting to hear from any ES drivers regarding this?

The ES has a larger 2.5 engine than the UX which is a 2.0 so that may also have an impact.

My dealer claims the over eagerness to rev is less in the ES than the UX but as you say it would be interesting to hear from other UX drivers as well as a few ES drivers (are there many yet?)

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Mash a traditional auto box and it will eventually swap down some gears and then accelerate with revs jumping up and down in the top third of the range whilst the car changes gear as they near the peak - when you ease off the car will swap cogs up the gears to a higher one for cruising. Mash a Lexus e-cvt and the revs rise to about 2/3 of max and the car accelerates - the revs then hold and/or continue to rise more slowly over the last third if you keep your foot to the floor - if you ease off the revs fall sharply as the car starts cruising at the set speed. That's the way the IS 300h drive train works. Rather than mash the pedal to the floor if you "squeeze" it to the floor over about a second or so then the revs rise a little more in line with speed. Also there is the kick down too - if you don't activate the kick down (so stop before you feel the kick down switch) the revs are more controlled (rather than just maxing out). If you mash the pedal to the floor the car uses the kick down switch for max torque/revs (similar to a traditional auto kick down that swaps to the lowest cog and the engine revs for max torque).

I always say that you really do need to drive a Lexus e-cvt car for a few weeks to "get" the way the drivetrain works. A few miles (or even a day) with the car and like anything "different" it feels strange. I had an IS 300h loan car for a day and made my decision to purchase after that but realise how much more I know now. But once you have experienced the e-cvt and get the feel of how it's working unless you drive the car like it's been stolen all the time it is a very refined piece of clever engineering that is more in tune with modern traffic than a traditional autobox - and I come from higher powered BMWs with autoboxes before I got my IS 300h and so have experience of a good autobox to compare it with. Not sure what car you had previously but I also drove a Merc C200 petrol hire car with auto about a year ago for a couple of months and have to say after the Lexus e-cvt it was atrocious - slow to respond, often in the wrong gear and certainly not smooth!

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2 hours ago, Sloth said:

John, in an ideal world or where you are buying the car perhaps but in the real world, the business world and one in which I am leasing for 3 years, I simply do not have the time to fart around with extended test drives on various cars. I therefore rely on short test drives, with refreshers as I feel the need and reviews.

I was aware of the CVT from reviews and the short test drives (3 in all over a couple of weeks) however despite it being different to my last standard auto, I made the decision that I could live with it and even get used to it.

My question was if there is a 'knack' to driving the CVT equipped car that may reduce my experience of high revs every time I try to accelerate.

I'm not decrying it or claiming it is not any good, simply asking if there is anything I need to know about driving style/technique regarding it.

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. 

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3 hours ago, Boxbrownie said:

You’ll get used to it, just a CVT characteristic. Personally I hate them and would pick a DSG type box any day over either a traditional TC or CVT box.

Having said that the Aisin box (traditional TC) in our old RX300 (and oddly enough in our old Freelander 2) was a gem.

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...

 

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I cant comment on the UX, but I had a CT200h which was keen to rev, but am now in an IS300h.  The IS accelerates a lot more quickly with less revs.  Unless I really mash it there is rarely need to exceed 2.5K so I think this will be similar to your ES experience unless you have a very heavy foot

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2 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...

 

But do not go anywhere near to a Nisan CVT box!

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