Why don't more cars use CVT?
Discussion
On the subject on Continuously Variable Transmissions...
Why don't more cars make use of these? Is it a consumer taste thing? Manufacturing cost?
The case for them, as I can see. I'm no great fan of old fashioned torque converter automatics although I've seen some reasonable ones, in the right car. My old A8 and Jaguar XJ were good because their V8 engines could simply throw petrol at the gaps in gear ratios to generate power and accelerate (and the A8 really could shift).
I've recently bought a CVT equipped hybrid and the technology seems to make great sense there. I was advised that the transmission would be a love-or-hate affair simply because it's so polarising in the way it operates. My experience of it is that it's a clever system which works well and seems to contribute to fuel savings, which is obviously a selling point for many cars these days. Even the most potent of cars now brag about their headline economy figures.
The downsides of the CVT are mainly the noise and sensation under acceleration. That is the first issue to address and what I reckon will account for the majority of drivers who don't like the CVT. The noise under heavy acceleration is a flat buzz. The acceleration doesn't feel that fast either because you don't have that noise to compare with the increased speed, you just get one tone that instantly stops when you reach your desired speed.
In their favour, they seem to suit smaller cars and hybrids because they can always find the best ratio for acceleration and cruising. My hybrid will cruise at 70mph at just over 1000rpm on occasion. My XJ would be around 2000rpm at the same speed. Because of the elastic response of the CVT, it's always willing to and able to instantly select the right ratio to provide instant acceleration when you open the throttle. There is no shuffling of gears or manipulating the throttle before a corner to precipitate a shift to the right gear, it seems to simply provide the best propulsion available at the drop of a hat before settling back to low rpm when you ease off the throttle.
Aside from under heavy acceleration, there is very little perceptible noise made. It's apparently both lighter and more mechanically simple than a torque converter box. It doesn't suffer from having to compromise a set selection of gears (and I've no doubt my car would be a dreadful drive with a traditional auto transmission much like every other small auto I've driven). Given the fact if has a lot going for it, why isn't the CVT more popular? It has gained a tiny bit more traction in America and Japan than it has in Europe, it appears.
It's never going to challenge a dual clutch box* or even an 8 speed auto for driving pleasure (it'd rob a sports car of it's revving noise!), bite as a solution for every day cars it seems ideal. There have been CVT equipped cars on the market for donkeys years, and manufacturers have the final say on what they fit. I wonder why it hasn't proliferated further?
Why don't more cars make use of these? Is it a consumer taste thing? Manufacturing cost?
The case for them, as I can see. I'm no great fan of old fashioned torque converter automatics although I've seen some reasonable ones, in the right car. My old A8 and Jaguar XJ were good because their V8 engines could simply throw petrol at the gaps in gear ratios to generate power and accelerate (and the A8 really could shift).
I've recently bought a CVT equipped hybrid and the technology seems to make great sense there. I was advised that the transmission would be a love-or-hate affair simply because it's so polarising in the way it operates. My experience of it is that it's a clever system which works well and seems to contribute to fuel savings, which is obviously a selling point for many cars these days. Even the most potent of cars now brag about their headline economy figures.
The downsides of the CVT are mainly the noise and sensation under acceleration. That is the first issue to address and what I reckon will account for the majority of drivers who don't like the CVT. The noise under heavy acceleration is a flat buzz. The acceleration doesn't feel that fast either because you don't have that noise to compare with the increased speed, you just get one tone that instantly stops when you reach your desired speed.
In their favour, they seem to suit smaller cars and hybrids because they can always find the best ratio for acceleration and cruising. My hybrid will cruise at 70mph at just over 1000rpm on occasion. My XJ would be around 2000rpm at the same speed. Because of the elastic response of the CVT, it's always willing to and able to instantly select the right ratio to provide instant acceleration when you open the throttle. There is no shuffling of gears or manipulating the throttle before a corner to precipitate a shift to the right gear, it seems to simply provide the best propulsion available at the drop of a hat before settling back to low rpm when you ease off the throttle.
Aside from under heavy acceleration, there is very little perceptible noise made. It's apparently both lighter and more mechanically simple than a torque converter box. It doesn't suffer from having to compromise a set selection of gears (and I've no doubt my car would be a dreadful drive with a traditional auto transmission much like every other small auto I've driven). Given the fact if has a lot going for it, why isn't the CVT more popular? It has gained a tiny bit more traction in America and Japan than it has in Europe, it appears.
It's never going to challenge a dual clutch box* or even an 8 speed auto for driving pleasure (it'd rob a sports car of it's revving noise!), bite as a solution for every day cars it seems ideal. There have been CVT equipped cars on the market for donkeys years, and manufacturers have the final say on what they fit. I wonder why it hasn't proliferated further?
- I should add that, were I designing the perfect sports car it'd be a manual with a TVR badge, though Porsche's PDK is fantastic.
I suspect the Volvo 300 series went some way to making these gearboxes seem uncool and therefore they might not have been as popular as they could have been.
In the 300 series there was a cool feature that reverse was as fast as drive! However, Joe Public made elastic band analogies and the car was pretty uncool so the innovative DAF technology was tarnished with an uncool reputation. Also, as you say, the set up is weird at first and certainly not sporty.
Anyone else have thoughts? I am happy to be disagreed with!
In the 300 series there was a cool feature that reverse was as fast as drive! However, Joe Public made elastic band analogies and the car was pretty uncool so the innovative DAF technology was tarnished with an uncool reputation. Also, as you say, the set up is weird at first and certainly not sporty.
Anyone else have thoughts? I am happy to be disagreed with!
IMO you've already answered the question, It's the constant engine noise (by which I mean the revs not rising, not the amount of noise) and the fact it feels different to any other sort of gearbox.
A lot of people by default "don't like" what's not familiar and are extremely conservative when making large purchases..
A lot of people by default "don't like" what's not familiar and are extremely conservative when making large purchases..
My bro-in-law managed to use a full tank of fuel in 90 Km, and arrived in a cloud of steam and fumes, in a hired Dodge Calibre CVT. He just planted the pedal and expected it to go faster. He, and I suspect a great many more drivers, needed a quick lesson on how to use it, and that might put a lot of people off, because it's 'different'.
karona said:
My bro-in-law managed to use a full tank of fuel in 90 Km, and arrived in a cloud of steam and fumes, in a hired Dodge Calibre CVT. He just planted the pedal and expected it to go faster. He, and I suspect a great many more drivers, needed a quick lesson on how to use it, and that might put a lot of people off, because it's 'different'.
How do you go faster then?I've often wondered the same thing,
I recently had a go in a Nissan Note CVT 1.2 DIG - S ( the 'S' is for supercharger.. I kid you not!)
It was great fun, eager, good economy and always willing. Once I'd figured it was a CVT and the clutch wasn't in fact buggered I was pleasantly surprised.
I wouldn't buy one myself, but I can see a lot of people need to give a modern CVT a chance.
I recently had a go in a Nissan Note CVT 1.2 DIG - S ( the 'S' is for supercharger.. I kid you not!)
It was great fun, eager, good economy and always willing. Once I'd figured it was a CVT and the clutch wasn't in fact buggered I was pleasantly surprised.
I wouldn't buy one myself, but I can see a lot of people need to give a modern CVT a chance.
Part of it could be a generational thing, there are a lot of buyers who still remember the old rubber band Daf versions and CVT is tainted by that.
For our sins we had a Daf44 in the fleet in the early 70s, whilst it didn't have much going for it, flat twin cylinder, air cooled, 6 volt electrics, one thing I remember was that it kept up with the flow of traffic far better than it should have done considering the 0-60 time of 32 seconds. It suffered in that due to the slow launch, centrifugal clutch, and the response time for the 'gears' to sort themselves out right at the start, but once rolling the engine and transmission were always in a sweet spot, if that's the right term, and one could roll along reasonably effectively, albeit not setting the road on fire.
Agree with OP that hitherto small petrol engined small cars and auto transmissions have not been a happy marriage. Have driven the odd vehicle with CVT and they've been quite OK, though iirc they all had got rid of the stepless nature of CVT by introducing artificial gear steps. That seems odd, deliberately making something work a bit less well by getting rid of the most important feature. Though some dual clutch transmissions deliberately make the changes a bit rough in order to be a bit sporty, so what do I know.
Final confession, always fancied a Kalmar as an oddball delivery van, based on the Daf44 and built for the Swedish post office, complete with Eberspächer heater to keep you nice and toastie.
For our sins we had a Daf44 in the fleet in the early 70s, whilst it didn't have much going for it, flat twin cylinder, air cooled, 6 volt electrics, one thing I remember was that it kept up with the flow of traffic far better than it should have done considering the 0-60 time of 32 seconds. It suffered in that due to the slow launch, centrifugal clutch, and the response time for the 'gears' to sort themselves out right at the start, but once rolling the engine and transmission were always in a sweet spot, if that's the right term, and one could roll along reasonably effectively, albeit not setting the road on fire.
Agree with OP that hitherto small petrol engined small cars and auto transmissions have not been a happy marriage. Have driven the odd vehicle with CVT and they've been quite OK, though iirc they all had got rid of the stepless nature of CVT by introducing artificial gear steps. That seems odd, deliberately making something work a bit less well by getting rid of the most important feature. Though some dual clutch transmissions deliberately make the changes a bit rough in order to be a bit sporty, so what do I know.
Final confession, always fancied a Kalmar as an oddball delivery van, based on the Daf44 and built for the Swedish post office, complete with Eberspächer heater to keep you nice and toastie.
Edited by FiF on Monday 25th January 08:03
We've just returned from a trip to the USA. We had a Nissan Altima rental car. This had a CVT box, but it drove more like a conventional auto - presumably the box has been programmed with fixed ratios, at least lower down the speed range. I think this might be the way to go?
I have heard many people say they don't like the way the engine behaves with a CVT, even my old Dad who had a friend who owned a DAF many years ago!
I have heard many people say they don't like the way the engine behaves with a CVT, even my old Dad who had a friend who owned a DAF many years ago!
Puddenchucker said:
DickyC said:
At present there is a limit to how much power you can put through CVT.
The Lexus LS600h has a 394hp V8 and a CVT.I know it's pedantic, but the Toyota and Lexus hybrids don't use a CVT transmission.
They behave in a similar way but it's not CVT.
I had an A6 for a while with. CVT (multitronic) it actually suited the car. It had what appeared to be pre programmed steps to simulate gear changes. However holding a steady throttle would see more traditional CVT behaviour and it would happily accelerate from 30 - 70 without changing revs. Was actually very relaxing.
My wife had a Mitsi Lancer with a CVT box and it was utter s
t. It literally drove me to sell it as it felt like you actually couldn't use the accelerator without sounding like an old granny trying to accelerate with the clutch down.
Now have a Murano which I initially rejected even considering due to the CVT but on driving found it surprisingly nice. Perhaps it's the large engine/more torque suits it better.
I have a 2000 E39 528 with a conventional auto and it still has a nicer gearbox than the 11 year newer Murano.
I'd be quite happy to never have a CVT ever again.
t. It literally drove me to sell it as it felt like you actually couldn't use the accelerator without sounding like an old granny trying to accelerate with the clutch down.Now have a Murano which I initially rejected even considering due to the CVT but on driving found it surprisingly nice. Perhaps it's the large engine/more torque suits it better.
I have a 2000 E39 528 with a conventional auto and it still has a nicer gearbox than the 11 year newer Murano.
I'd be quite happy to never have a CVT ever again.
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