OutdoorKing Repair Forum Forums General Discussion Forum Off Topics Which is better? CVT or Manual?

Has anyone driven a CVT vehicle? I love the concept but am beginning to wonder if the lack of audible gear changes and constant wavering of the engine drone would drive you mad after a while? It is an excellent concept as far as keeping the engine in it's peak revs at all times.
The comparison, though is more complex after thinking it over. Yes, engines generally have a specific peak power output level, say 5000 rpm, but maybe you don't need that peak power 100% of the time. 60 or 80% may suffice for the great bulk of driving and those levels of power are probably accessible through a greatly expanded rev band, which a fixed gear in a manual can easily exploit, I theorise.
CVTs, despite being available in some cars for over fifteen years, are still giving problems as they are inherently fragile and subject to strain.
The CVT in the 1.2l 3 cylinder Mitsubishi Mirage is designed to take up to 150 hp, but as the engine in the Mirage only puts out 74hp, they should be unstressed and last lots longer then average CVTs. I have watched videos of both versions of the Mirage and the manual version seems more spritely and a lot more fun, but the CVT only sits on 2000rpm at 100km/h , compared to 3000 for the manual's fifth gear.

G'day MF
A great question to which I will add my 2-cents.
The continuously variable transmission comes in a number of forms.
I guess, just like gear boxes, there are good and bad ones.

https://en.wikipedia.org/wiki/Continuously_variable_transmission

For example, the CVT on my MP400 motor trike is total rubbish.
It is harsh on take-off and in bumper-to-bumper traffic.

In a Toyota Corolla Hybrid it works like a good automatic.

In all cases, the CVT should deliver best fuel economy -
provided that criteria was part of the design...

But, as you say, the issues are more complex.

The CVT on vehicles is older than folks think.
I remember an old doco that covered this odd vehicle...
{I think one of these crossed AUS East-West ...

https://en.wikipedia.org/wiki/Variomatic

If you like driving - CVTs are not the best choice.
They average out to optimize energy consumption and performance.
Manuals enable choice for the Dr Jekyls and Mr Hydes amongst us.

Cheers
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Jack

I have heard that auto manufactures were experimenting the CVT designs. But as Jack said I am a manual person when given the choice over anything automatic. Definitely hate those consumer rental equipment with the hydrostatic drives; so limited what they can when compared to my tractor with a manual transmission.

The only CVT transmissions I have experience with and it is limited is the ATVs and UTVs which not seen a lot problems but these are off the road vehicles. Some these do have multi-speed manual transmissions attached but there is no shifting on the fly.

The book is out on the General Transmissions RS800 CVT transmission as I have only seen one. Not a whole lot confident in the plastic housing and do seen several complaints the last few years performance issues.

If my understanding of the CVT is correct it eliminates the slippage of the automatic torque convertors which depends fluid resistance to drive components. With the CVT there is no slippage except at idle speeds. I just wondering if they are still going use fluid version of the automatic to drive a multiple speed transmission shifting as the CVT in my thinking would just need to replace the torque convertor.

Here is the Jatco CVT7 as used in the Mitsubishi Mirage. It features a high and low range auxiliary gearbox to increase ratio spread and has a lock up torque convertor. This is a fancy bit of kit for a sub compact car in the lowest price category.

I haven�t had much to do with CVTs in cars but I used to work at a Case IH tractor dealership so serviced a lot of CVT tractors.

You select the speed range whilst stationary and then the throttle pedal or hand throttle position controls the speed. It enables precise �inching� for hitching up implements etc but there�s also a mode to select a certain PTO speed and the engine revs & ground speed will vary automatically to suit the load.

The Jatco JF506E automatics proved to be very troublesome in the Jaguars & Land Rover Freelanders. Hopefully they�ve improved reliability by now!

The Jatco 4 speed overdrive transmission in my 89 Laser has proven trouble free in the 60,000km I have driven, but the shift quality has never been stellar.
Snowmobiles use CVT as well, I believe, but I imagine that is a specialised application where CVT comes into it's own and very different operating conditions to a car.
Nissan are game using it on some of their V6s now! Will we ever have a V8 running a CVT? I'd like to see that.
Leyland even experimented with a prototype on a full size bus back in the early 80s and it showed promising results in a 6% saving in fuel, but the transmission, unsurprisingly kept getting too hot.