eli5: Why does a CVT transmission still “shift” if it can be in any position and move seamlessly as they say?
In: 579
I just bought a 2020 Blazer and it’s seamless shifting. I love it. Just goes and goes, smooth as can be.
2015 Pathfinder with 64,000 Miles. Still going strong but I notice it doesn’t like when a fake “shift” drops the RPM too low under light throttle. It stutters.
It becomes a game of “avoid the shift” where you progressively press the gas pedal or let go of the gas completely to avoid the stutter.
In conclusion, Nissan CVTs suck balls and the fake shifts are where the problem is most noticeable. Ultimately, replacing the transmission will cost less than a used car though.
To remove that annoying monotonous sound and vibration of an engine not fully loaded up, but still holding a given rev figure.
I wonder if Subaru also wants to make it less obvious that it’s a CVT. The CVT in certain years of the Outback is infamous for poor reliability. Just make it perform the same as a slushbox and call it an automatic.
I actually liked the experience when I had a Nissan with a “no shift” CVT, but of course some people can’t handle change and we all know angry people are the loudest ones.
Hi OP,
Actually, it is a bit more complicated than “it’s done to fool non-CVT drivers”, at least in certain cases.
Take the Nissan Sentra, Versa and Micra. Between 2010 and 2016 they used a particular CVT transmission made by Jatco (who supplied Subaru, Mitsubishi and others) called the JF015e. When it was introduced, it was hailed as an innovative design. In an effort to reduce weight and size, two things were added: two separate high/low clutches, and an additional planetary gearbox. This allowed for space savings of over 15 percent — not insubstantial in economy cars — and allowed for neat tricks like not requiring the belt to turn the other way when in reverse. The consequences of these separate clutches and gearboxes engaging, though, is noticeable and predictable changes in engine RPM. People would say “huh, feels like my CVT is changing gears”, and if they had a JF015e… in a way, they were right!
Now it turns out that the JF015e was a cursed design. It was EXTREMELY intolerant to debris shed by the belt — a normal occurrence in CVTs — and this would circulate in the fluid and score the bores of the solenoids in the valve body. This would lead to all sorts of nastiness all the way up to catastrophic failure. Nissan recently lost a large class-action targeting this transmission, as the only way to have prevented it was to have fluid changes far more aggressively than mandated by the manual… think 30k km for a transmission fluid change.
Tl;dr: there are other reasons for the shifting feeling… including actual shifting!
Because people are retarded enough to complain about lack of gears switching as you don’t get the HURRR DURRR IMMA BESTEST DRIVER LET’S GO when it’s continuous.
It only shifts like that with hard acceleration. I’m not sure if it does that to get to a more suitable gear ratio quicker or just for aesthetics.
Either way you can test this by slowly accelerating from 0 to 100 kph for example and you’ll notice that it doesn’t shift and just continuously gets faster while maintaining a decent RPM that doesn’t change much.
It is mostly due to consumer preferences.
Early CVTs adjusted the ratio continuously so that the engine operated at optimal RPM for maximum efficiency while delivering the requested acceleration.
When operating like this, the engine RPM doesn’t change in correlation to the vehicle speed. For example, when pulling away from a stop light, the engine RPM might rise to 2,800 RPM, then stay there as the CVT alters the gear ratio to provide acceleration.
Many consumers complained bout the drone of the engine when operating like this. The sensation was compared to that of a boat, and the majority of consumers didn’t care for it.
In response, manufacturers introduced artificial “steps” so that the engine RPM would rise with velocity, then fall in steps just like a regular transmission. Behind the scenes though, the CVT is still adjusting the ratios to provide better fuel economy. Just not to the degree that it could.
So its to make it feel like a normal automatic, basically when they first came out people were unnerved by their car not shifting. I think it’s dumb that they’re trying to make it seem like an auto, it should be it’s own thing and I don’t believe it should completely replace other kinds of transmissions. I much prefer an automatic with actual physical gears, not because “hurr durr” as people in this thread have said, but I feel they last longer. Also I don’t enjoy the traditional faults that cvts have, the stuttering being the main one. Of course not all do this, but it’s a co.mon enough thing and isn’t even an indication that something is wrong, it’s just what the particular model I drove did. Trying to go from a stop would cause a second or two of stuttering, making attempting to turn onto a busy road much more anxiety inducing. Also as a plus, since I have a 6 speed auto, my flappy paddles do actually do something. Maybe that’s a little “hurr durr car go fast” but I bought a sports car, I have a reason for it. And the reason is fun.
Latest Answers