4 ms·

There's also torque converters, which are a hydraulic mechanism. This is the basis of most (non sporting) automatic transmissions. Higher performance torque con

There's also torque converters, which are a hydraulic mechanism. This is the basis of most (non sporting) automatic transmissions. Higher performance torque converters have a lock up mechanism that functions as a clutch making it rigid at high speeds. So you can kinda get both.

masklinn 4y ago
> There's also torque converters, which are a hydraulic mechanism. This is the basis of most (non sporting) automatic transmissions. By virtue of being the dominant automatic transmission in the US, where automatic transmission is the overwhelming majority. In Europe, torque converters have never been much of a thing, historically because of the small engines (at the low end, and demand for control and responsiveness at the high end), and more recently for efficiency reasons. AT has been shooting up in popularity (in parts because gearings have been getting shorter which makes manual transmissions really annoying), but mostly on the back of DCTs, even at the low end e.g. these days it's pretty common to find a 6-speed DCT on a B-segment car, and C-segments getting 7 or 8-speed DCTs (AMTs sadly still survive at the lower end of AT, but I feel CVTs are eating their bacon, especially with progressive hybridation).
- SigmundA 4y ago
  Modern lock-up torque converter transmissions have pretty much eliminated any efficiency gains from other designs, I believe everyone is moving to them even in Europe. I know here in the US many care from various manufacturer are coming with German designed ZF transmissions including the 9 speed in my Honda Pilot. https://www.autocar.co.uk/car-news/technology-news/under-skin-why-torque-converters-are-coming-back-dead https://www.autocar.co.uk/car-news/technology-news/under-ski... https://www.caranddriver.com/features/a23367341/automatic-transmission-best-zf-eight-speed/ https://www.caranddriver.com/features/a23367341/automatic-tr...
- CRConrad 4y ago
  > In Europe, torque converters have never been much of a thing, historically because of the small engines [...] and more recently for efficiency reasons. The small-engine problem was basically just another aspect of the efficiency problem: Torque converters used to be so inefficient that if you had very little power to begin with, close to none at all got through to the drive wheels.

masklinn 4y ago

> There's also torque converters, which are a hydraulic mechanism. This is the basis of most (non sporting) automatic transmissions. By virtue of being the dominant automatic transmission in the US, where automatic transmission is the overwhelming majority. In Europe, torque converters have never been much of a thing, historically because of the small engines (at the low end, and demand for control and responsiveness at the high end), and more recently for efficiency reasons. AT has been shooting up in popularity (in parts because gearings have been getting shorter which makes manual transmissions really annoying), but mostly on the back of DCTs, even at the low end e.g. these days it's pretty common to find a 6-speed DCT on a B-segment car, and C-segments getting 7 or 8-speed DCTs (AMTs sadly still survive at the lower end of AT, but I feel CVTs are eating their bacon, especially with progressive hybridation).

SigmundA 4y ago
Modern lock-up torque converter transmissions have pretty much eliminated any efficiency gains from other designs, I believe everyone is moving to them even in Europe. I know here in the US many care from various manufacturer are coming with German designed ZF transmissions including the 9 speed in my Honda Pilot. https://www.autocar.co.uk/car-news/technology-news/under-skin-why-torque-converters-are-coming-back-dead https://www.autocar.co.uk/car-news/technology-news/under-ski... https://www.caranddriver.com/features/a23367341/automatic-transmission-best-zf-eight-speed/ https://www.caranddriver.com/features/a23367341/automatic-tr...
CRConrad 4y ago
> In Europe, torque converters have never been much of a thing, historically because of the small engines [...] and more recently for efficiency reasons. The small-engine problem was basically just another aspect of the efficiency problem: Torque converters used to be so inefficient that if you had very little power to begin with, close to none at all got through to the drive wheels.