CVT - why all the hatred?

Joe_Horner

I did ask this on a related thread, but no-one seems to be coming up with anything other than "they're horrible". So I thought I might get more sensible answers if I asked in a new thread.

Assuming they're set up properly CVTs are by far the most efficient and responsive trasmissions out there and, by their inherent nature, wring the maximum possible performance and economy out of a given engine.

Granted, you can't get away with abusing them with lack of maintenance to the same extent you can with a manual or slushbox, but the same applies to modern engines compared to 1970s cast iron OHV boat anchors - and I don't see many people suggesting that we should be sticking to those!

And you don't get creep at idle, but you don't get that in a manual either but people still manage to park or do hill starts with millions of manual cars, perfectly safely, every day.

So what (properly reasoned) points do people have against CVT?

TrickyWicky

Not that I have a cue what CVT is but..

Joe_Horner wrote: »

And you don't get creep at idle, but you don't get that in a manual either but people still manage to park or do hill starts with millions of manual cars, perfectly safely, every day.

With no creep and using a clutch its is a bit of effort to get things right. Granted you get used to it but with the creep life is just a lot easier. One pedal does everything for you.

gilbert_and_sullivan

Nothing at all wrong with good ones, box in Avensis is a dream, as smooth to drive as any TC box, infinitely controllable at manoeuvering speeds too, whether it has creep i can't recall.

Maybe people are still wary of being burned, as owners of certain models have been when they go wrong, Fords poor effort as fitted to Cmax 1.6d, and Audi's Multitronic are two that spring to mind.

Yes they are efficient, but when TC auto boxes last the life of the vehicle (mine's 18 and as smooth as the day it was made) with just periodic oil changes, then the old standard of if it aint broke don't fix it comes into play, not everything new and stuffed with technology is necessarily best in the long term.

We'll see in due course how many DSG/automated manual/CVT boxes are still running well at that age, i suspect in practice that such boxes will help prematurely write many vehicles off, a simple TC box might well be an easy economical overhaul, the others arn't.

nobbysn*ts

I have driven Avensis 2.0l S-CVT, with 4 heavy people in it. Car has 154hp or something like that. When we came to uphill, we had to gun it to keep up with rest of the guys, and what that means is stepping on the pedal, rpms go to 5400 and stay there and seemingly nothing happens, just engine noise. It wasn't a nice experience - comment from another website by some that can remember the experience.

knightstyle

We have owned a Toyota Auris 1.4diesel with the MMT box that everyone seems to hate for the last four years. We soon got to like it and driven sensibly, not slowly, we got over 50mpg. Unheard of for an automatic a few years ago.
Yes you needed to lift off slightly when the box changed gear when accelerating but you do that with a manual don't you?
We have just changed it for a Nissan Juke 1.6 petrol with a belt type auto box and a fluid flywheel, it certainly gives a smoother gear change but it seems more sluggish unless in sport mode and the fuel consumption in normal mode is only 36mpg.
We would buy another CVT box but fancied something a bit less "grey" than than the Auris.

gilbert_and_sullivan

Toyota's MMT box isn't an automatic, its a manual box with gears and clutch just like a normal manual, except that computers and solenoids make a hash of selecting the wrong gears and messing up clutch engagment instead of the person behind the wheel...;)

How is a slower Juke less grey than a faster Auris?

Joe_Horner

Interesting looking at the two examples people have given (Avensis and Juke) that both give better performance on paper in the manual version than in CVT. That can only mean that the CVT system is not set up optimally for the car.

The whole point of CVT is it allows the engine to work within its optimum efficiency / power band at all times. By definition, that means that it will give better performance than a manual, where you inevitably end up outside the band at times. Hence the 1 - 2 seconds or so per lap that Williams saved in the early '90s just by sticking a CVT on the back of an otherwise identical F1 car (and promptly getting the system banned before it raced). Wonder if they'd been allowed to race it would peoples attitudes now would be any different?

The whole thing of "sports mode" in a CVT is also an odd marketing strategy. There's no need for it other than giving a more "sporty" engine sound. Most people judge acceleration (at least partly) by the rising engine speed - it's not an accurate gauge but it's what people learn to do. So yes, the monotonous high revs of a CVT when you boot it can "seem" to be sluggish when, in fact, what it's doing is laying the most power possible onto the road at all times.

Maybe it's one of those areas where perception (and possibly manufacturers' attempts to "normalise" that perception) gets in the way of reality.

cardinalbiggles

I had a 1993 Fiat Panda Selecta which was a 1.1 with CVT shared with I think Subaru or something. It was 55bhp and did 0-60 in just under 10 seconds. It lasted 138k miles before I sold it and got me through my student years.

I would certainly not hesitate to have another one.

bigjl

They got a bad rep from the off with the box fitted to the Micra and mk2 Fiesta.

They are very reliable in the Prius.

Though personally the only car i would have a cvt box in would be a Prius.

Not sure if the Honda Insight has a cvt box, i suspect it does, that would be another candidate in my boom if it does have a cvt fitted.

Some people just don't like the constant engine note.

Probably suit urban motoring best.

oldagetraveller

"And you don't get creep at idle,"
I have a Multidrive-s (C.V.T.) Yaris and that definitely "creeps" at idle. Torque converter with low speed lock up clutch.

"Some people just don't like the constant engine note."
? It's not constant though. In fact depending on conditions it does sound as though there is clutch slip when a lower ratio is selected as the accelerator is depressed for uphill etc.. I would suggest that's what concerns people until they realise that's normal.
I suspect that many of the critics have neither ever driven one nor owned one and just quoting internet searches.:)

knightstyle

g&s I didn't say te Juke was slower than the Auris, it just feels sluggish but this could be due to the CVT changing gear at lower revs when in normal mode.
It is my wife who says it is less grey! I have to agree as it it red!