5 ms·

CVT's are 100% pure trash. Dig the ZF8 in my RAM a lot. Did not like the 10 speed in my F-150, ZF is much better.

zubiaur 3y ago
Agree on pure IC ones. Hybrid ones, like the one on the Prius, while still technically a CVT, are nothing like the jatco crap Nissan and others had been putting on IC cars. They are quite reliable.
- kQq9oHeAz6wLLS 3y ago
  The later Nissan CVTs are apparently fine, although they were unable to overcome the damage done to their reputation.
- brendoelfrendo 3y ago
  The "eCVT" in the Toyota hybrid system isn't a CVT at all, but rather a system that uses the electric motors with planetary gearsets to keep the engine operating as close to its optimal RPM as possible: https://youtu.be/O61WihMRdjM?si=hPoLm8EZnbiLH60h https://youtu.be/O61WihMRdjM?si=hPoLm8EZnbiLH60h
hinkley 3y ago
I think it was Honda who tried out a 2 motor planetary gear setup to eliminate the transmission and I don't know why it was abandoned because it was brilliant. The idea was that you need a certain velocity and torque to hold the drive train at a given speed, and instead of using reconfigurable gearsets for that, you use a differential, and one of the output shafts is sometimes an input shaft. One of the output shafts is attached to the wheels, the other to a motor. At some speeds output shaft B is stationary. To accelerate, you feed power into the motor and now it's speeding up shaft A. At lower speeds, you bleed power off of shaft B by running the motor as a dynamo, using it to charge the batteries and run auxiliary equipment. In the hybrid version there was an ICE on the input shaft (or an ICE and a ganged electric motor) but on a full electric you could run two motors with different torque curves and balance the inputs for each speed.
- organsnyder 3y ago
  My Pacifica PHEV has that configuration. It works very well.
- kube-system 3y ago
  Toyota is the manufacturer famous for their 2-motor planetary setup (they call it Hybrid Synergy Drive), and they've licensed it to a couple of other manufacturers, like Ford and Nissan. Honda's old system, 'IMA', which was a traditional ICE drivetrain with a motor assist. They abandoned it because mild hybrids don't really deliver a good value. It's a lot more cost for not very much improvement in economy. Honda's new system, E-drive, usually operates like an EV with a generator attached, but it also has a lock-up clutch to allow the engine to direct drive the wheels in cruising conditions.
  - dragontamer 3y ago
    > 2-motor planetary setup (they call it Hybrid Synergy Drive) 3-motor actually. https://eahart.com/prius/psd/ https://eahart.com/prius/psd/ 2x Electric Motors + 1x ICE motor. Its a bit confusing but there's a lot of Youtube demos, webpage-demos, and simulations to help you understand how it all works.
    - kube-system 3y ago
      Hybrids with 2 motor-generators and one ICE are usually called "two motor" hybrids.
  - hinkley 3y ago
    I’m irritated that I initially thought “Toyota, or wait, was it Honda?” And picked wrong.
queuebert 3y ago
The 10R80 in the F-150 has known problems, while the ZF8 is one of the best transmissions currently made. It's also used in BMWs, the Toyota Supra, and the new Ineos Grenadier. Having driven it, my only issue was that it was slow to switch from deceleration/engine braking mode to acceleration mode. That programming allows it to feel more like a manual when you let off the gas, but it takes a good fraction of a second to switch between them.
- whalesalad 3y ago
  My truck in tow/haul mode behaves very well with engine braking. Very responsive. I’m guessing it’s a software thing.

Agree on pure IC ones. Hybrid ones, like the one on the Prius, while still technically a CVT, are nothing like the jatco crap Nissan and others had been putting on IC cars. They are quite reliable.

kQq9oHeAz6wLLS 3y ago
The later Nissan CVTs are apparently fine, although they were unable to overcome the damage done to their reputation.
brendoelfrendo 3y ago
The "eCVT" in the Toyota hybrid system isn't a CVT at all, but rather a system that uses the electric motors with planetary gearsets to keep the engine operating as close to its optimal RPM as possible: https://youtu.be/O61WihMRdjM?si=hPoLm8EZnbiLH60h https://youtu.be/O61WihMRdjM?si=hPoLm8EZnbiLH60h

hinkley 3y ago

I think it was Honda who tried out a 2 motor planetary gear setup to eliminate the transmission and I don't know why it was abandoned because it was brilliant. The idea was that you need a certain velocity and torque to hold the drive train at a given speed, and instead of using reconfigurable gearsets for that, you use a differential, and one of the output shafts is sometimes an input shaft. One of the output shafts is attached to the wheels, the other to a motor. At some speeds output shaft B is stationary. To accelerate, you feed power into the motor and now it's speeding up shaft A. At lower speeds, you bleed power off of shaft B by running the motor as a dynamo, using it to charge the batteries and run auxiliary equipment. In the hybrid version there was an ICE on the input shaft (or an ICE and a ganged electric motor) but on a full electric you could run two motors with different torque curves and balance the inputs for each speed.

organsnyder 3y ago
My Pacifica PHEV has that configuration. It works very well.
kube-system 3y ago
Toyota is the manufacturer famous for their 2-motor planetary setup (they call it Hybrid Synergy Drive), and they've licensed it to a couple of other manufacturers, like Ford and Nissan. Honda's old system, 'IMA', which was a traditional ICE drivetrain with a motor assist. They abandoned it because mild hybrids don't really deliver a good value. It's a lot more cost for not very much improvement in economy. Honda's new system, E-drive, usually operates like an EV with a generator attached, but it also has a lock-up clutch to allow the engine to direct drive the wheels in cruising conditions.
- dragontamer 3y ago
  > 2-motor planetary setup (they call it Hybrid Synergy Drive) 3-motor actually. https://eahart.com/prius/psd/ https://eahart.com/prius/psd/ 2x Electric Motors + 1x ICE motor. Its a bit confusing but there's a lot of Youtube demos, webpage-demos, and simulations to help you understand how it all works.
  - kube-system 3y ago
    Hybrids with 2 motor-generators and one ICE are usually called "two motor" hybrids.
- hinkley 3y ago
  I’m irritated that I initially thought “Toyota, or wait, was it Honda?” And picked wrong.

queuebert 3y ago

The 10R80 in the F-150 has known problems, while the ZF8 is one of the best transmissions currently made. It's also used in BMWs, the Toyota Supra, and the new Ineos Grenadier. Having driven it, my only issue was that it was slow to switch from deceleration/engine braking mode to acceleration mode. That programming allows it to feel more like a manual when you let off the gas, but it takes a good fraction of a second to switch between them.

whalesalad 3y ago
My truck in tow/haul mode behaves very well with engine braking. Very responsive. I’m guessing it’s a software thing.