Can someone explain to me why CVT = bad?

[TheJimi]

I've never actually driven a car with CVT, but one happens to be on my shortlist for my girlfriend's next car.

I often see negative commentary on here where CVT is concerned, and I can't fully grasp why this is.

[soxboy]

There’s nothing ‘wrong’ with it, it’s just different.

It mostly stems from people who’ve come from manual transmissions, where the noise of a CVT not only varies disproportionately to engine revs but also sounds like a clutch slipping.

[vikingaero]

If it's a normal shopping trolley for getting from A to B then it's fine. If you want a drivers car then no.

CVT are used in loads of cars from Hondas to Prius's's's's and many used as taxis.

I bought a 2018 Honda Jazz for my Mum and she has since returned it to me as my parents are happy with one car and live near a bus stop with a bus every 10 minutes. As I'd paid for the car, paid for servicing, insurance and VED, I thought I would use it. And I hated it. Slow and the CVT box is noisy when pedalled hard.

Then with a few trips into London it made sense. The softer CVT action makes many torque converters seem harsh and DSG's are jerky monstrosities in comparison. The action of a CVT make braking much smoother and the same with acceleration, if you're not in a hurry. It's relatively low revving for a petrol engine at 50-65mph which is about right for city clearways.

I've grown to like it quite a lot.

[littleredrooster]

As much as anything, I suspect that it's a 'convention' thing because it is so different. When acceleration is called for (i.e. throttle is opened), the revs 'flare' without any increase in speed initially and some people find this slightly alien I think.

Our daily is a Prius which we've had for almost 7 years, so I am well used to it, but people still remark on the way the engine revs under an increase in load.

(...and yes - technically, the Toyota hybrids don't actually have a CVT as such, just a fairly simple power-splitter with an epicyclic gear set and clever power inputs and outputs, but it has the same overall effect without troublesome belts and stuff)

[tr7v8]

I'll leave this here:- https://www.youtube.com/results?search_query=cvt+t...

[kambites]

soxboy said:

There’s nothing ‘wrong’ with it, it’s just different.

It mostly stems from people who’ve come from manual transmissions, where the noise of a CVT not only varies disproportionately to engine revs but also sounds like a clutch slipping.

Although it's also worth noting that historically they haven't tended to be the most reliable of things.

[Snow and Rocks]

kambites said:

Although it's also worth noting that historically they haven't tended to be the most reliable of things.

It is worth pointing out that, as another poster mentioned above, the Toyota hybrid system isn't a traditional unreliable belt driven setup despite being marketed as an e-CVT.

In reality, it's pretty much bulletproof with no wearing parts or maintenance requirements - certainly more reliable and durable than typical traditional autos or even manuals in my opinion.

They're actually nice to drive in a non-sporty car too once you get used to it, especially if you get with with plenty of grunt. They certainly make something like a chuntering 4 pot tdi with a jerky DSG feel pretty old fashioned.

[benoliver999]

Tried one in a Juke, it was painful. Tried one in a Honda Insight, not so much. On the reliability front, the Insight went well over 250k miles before they got rid.

As others have said it's purely what you're used to. As a concept it's not that bad, and actually pretty clever.

[valiant]

kambites said:

Although it's also worth noting that historically they haven't tended to be the most reliable of things.

Generally because manufacturers sell them as ‘sealed for life’ when they are anything but and so maintenance is ignored. They only need a fluid change every 50k or so and they’ll last as long as the rest of the car.

[Box Fresh]

Try one, you’ll decide pretty quickly.

[Puddenchucker]

A couple of years ago, I had a Nissan Note with a CVT as a courtesy car and I was impressed with the smoothness of the transmission.
In fact, I think I'd prefer it to the DSG in my current daily driver.

[kambites]

valiant said:

kambites said:

Although it's also worth noting that historically they haven't tended to be the most reliable of things.

Generally because manufacturers sell them as ‘sealed for life’ when they are anything but and so maintenance is ignored. They only need a fluid change every 50k or so and they’ll last as long as the rest of the car.

Conventional CVTs realistically need belt replacements if you're going to get big mileages out of them. Although admittedly they tend to be fitted to the sorts of cars which don't do many miles.

[WelshPetrolhead]

My only experience of a CVT was the multitronic unit in a 3.0TDI Audi A6. I really liked the way it drove, really nice smooth cruiser. I also had the system regularly serviced. Would happily consider another car with that kind of setup

[kambites]

Snow and Rocks said:

It is worth pointing out that, as another poster mentioned above, the Toyota hybrid system isn't a traditional unreliable belt driven setup despite being marketed as an e-CVT.

Yeah, I wouldn't really consider the Prius to be a CVT.

[Evanivitch]

The Ampera wasn't CVT but it had the same detached engine load to road speed characteristic about it. As a generator it was even worse because sometimes it would be idling high recharging battery even at traffic lights.

I don't mind them as a daily, as long as they're not daft enough to out artificial shifts in it.

[J4CKO]

CVT seems to have become the equivalent of how back in the old papery AutoTrader days when you were checking out potential cars and found a suitable one, then realised it was an auto.

[Starfighter]

My wife has an Auris hybrid with a CVT. the high sustained revs on acceleration and under heavy load take some getting used to. The car feels a whole lot better in performance mode but I suspect that is more the power delivery rather than gear box.

Over it is perfectly usable but not engaging.

[Cass63]

I’ve got a Lexus rx400 with a cvt gearbox and hybrid engine, accelerates like a rocket, the feeling of a slipping clutch takes some getting used to but you soon forget about it and it only does it under heavy acceleration.

[Bobupndown]

Never driven one but like the look of Subaru Outbacks which mainly seem to come in cvt format.
I'd want a very long test drive to see if I could live with one.

[Plymo]

They're not bad at all - they are used on practically every moped & scooter for the past few decades, and in that application they do an excellent job of getting the most out of the measly power available, smoothly. They really are great, they let the engine get up to revs for peak power, and keep it there until you ease off the throttle.
In cars, my partner has a MK2 Prius, which although apparently is not technically a CVT transmission it behaves pretty much like one, you just have to get used to revving it right up to get enough power. It's very smooth though.

I think their bad reputation comes partly from people not being used to how they feel like they're "slipping" when accelerating (it's not, it's just keeping the ratio low enough to keep the engine revs where they give the most power) and partly from them often being coupled to an already gutless engine.

Again, the Prius ones are well known to last ages - so do the engines, perhaps because the transmission is gentle on the engine, as it lets it rev freely but never puts it in a high-load/low-rev situation, and there's no shock from abrupt gear changes.