What is the point of paddle shifters with a CVT?

[brent_w]

My question isn't exactly the same as the useful or gimmick thread.

It might be because I'm new to the concept of the CVT.
But I don't seem to understand the very purpose of the paddle shifters in a car with that type of transmission.


With your more traditional automatic transmission, like the one in the fit, the function and purpose of the paddle shifters makes sense.


A CVT, of course, has no "gears". The number of possible ratios is, theoretically anyways, infinite.
As I understand it ... the computer selects the best ratio for the moment and makes it so.

In that sense ...
Wouldn't forcing the transmission, that can select any ratio it wants, into a strict 7 different arbitrary ratios essentially be akin to shooting the CVT in the foot?

The odds of one of those 7 being the most efficient or effective ratio for the situation seems pretty low ... if the computer can choose a ratio in between two of the gears that would be better for the situation ... wouldn't the driver just be better off not touching the paddle shifters altogether?


I'm probably missing something here ... like maybe the computer's "intelligence" when it comes to ratio selection isn't all it's cracked up to be ... so I'm hoping someone can enlighten me.

[gomarlins3]

I use it when autoXing, otherwise I let the computer do the thinking. Bums me out that it won't hold a gear when coming up to redline even in 'manual' mode.

[atteSmythe]

Originally Posted by brent_w

In that sense ...
Wouldn't forcing the transmission, that can select any ratio it wants, into a strict 7 different arbitrary ratios essentially be akin to shooting the CVT in the foot?

The odds of one of those 7 being the most efficient or effective ratio for the situation seems pretty low ... if the computer can choose a ratio in between two of the gears that would be better for the situation ... wouldn't the driver just be better off not touching the paddle shifters altogether?

I'm probably missing something here ... like maybe the computer's "intelligence" when it comes to ratio selection isn't all it's cracked up to be ... so I'm hoping someone can enlighten me.

Well, it's the efficiency versus effectiveness argument, I suppose. When you put your foot on the accelerator, the car doesn't know whether you want to sacrifice fuel economy for more responsiveness, it just has to guess as best it can. The paddle shifters let the car know that you need it to act differently than it normally would in that situation. And, unless you're in sport mode (IIRC), the paddle shifter's override of the ratio times out after a while, and the computer takes over again.

So no, it's not a flaw in the computer's ratio choice, per se, but just that its optimization goal may be different than the driver's.

[brent_w]

Originally Posted by atteSmythe

Well, it's the efficiency versus effectiveness argument, I suppose. When you put your foot on the accelerator, the car doesn't know whether you want to sacrifice fuel economy for more responsiveness, it just has to guess as best it can. The paddle shifters let the car know that you need it to act differently than it normally would in that situation. And, unless you're in sport mode (IIRC), the paddle shifter's override of the ratio times out after a while, and the computer takes over again.

So no, it's not a flaw in the computer's ratio choice, per se, but just that its optimization goal may be different than the driver's.

I suppose I assumed they would naturally make the computer focus on efficiency in econ mode ... focus on power in sport mode ... and split the difference in normal mode.

And from a computer science perspective ... these days I would expect smarter algorithms. The software should be intelligent enough to gradually shift the focus on the fly, particularly in normal mode, in order to adapt to the the driving style of the user.

If they are being heavy footed ... the computer would shift towards more powerful ratios.
Lightfooted ... or driving patterns indicative of heavy traffic ... the computer would shift towards more economic ratios.

[sleighman]

I have been using the paddle shifters a lot in sport mode and what I have found is that if you get in sync with the car, the car responds very nicely. 1st, 2nd, 3rd and 4th flow very well and down shifting to set up for short quick corners holds the reve's till you are ready to shift.

In any mode other than sport the paddle shifters are useless.

I personally like them.

[ErikTheRed]

During my commutes home in Econ mode I would shift down a gear or 2 based on how fast traffic is slowing to provide more engine braking and reducing the wear on the break pads.

[Ludercrz]

Originally Posted by gomarlins3

Bums me out that it won't hold a gear when coming up to redline even in 'manual' mode.

unfortunately they do that in Every automatic car with a "sport-tronic" like shifting interface. They assume you forgot you had it in sport shift mode and up shift for you when you approach redline too rapidly.

what I hate the most is the 0.5 to 1sec it takes after you press the up shift for it to actually change gear sometimes.

which is why I buy my cars Manual. i can't stand not being in control when I need it.

[Scotty001]

Overthinking....

Just to add a little potential fun to the CVT when you want it.

[human668]

Originally Posted by Ludercrz

unfortunately they do that in Every automatic car with a "sport-tronic" like shifting interface. They assume you forgot you had it in sport shift mode and up shift for you when you approach redline too rapidly.

what I hate the most is the 0.5 to 1sec it takes after you press the up shift for it to actually change gear sometimes.

which is why I buy my cars Manual. i can't stand not being in control when I need it.

not every automatic car. The automatic gearbox on my TSX lets me hold a gear and bouncing off rev limit.

[northbridge]

^ +1 the TSX does let you hold a gear and at redline there is a fuel cutoff