Manual vs automatic What is desirable for MPG?

[cRiPpLe_rOoStEr]

Originally Posted by jakobnev

Best of both worlds(?), the automated Manuel transmission

Single-clutch AMTs were unsuccessful for cars in my country, even though it's a more popular option for commercial trucks than conventional automatics. Odd enough, some bus frames are offered with the option for an AMT, yet it's not so favored by fleet owners who prefer manuals whenever it's still allowed or go for a conventional automatic whenever it's mandatory.

[some_other_dave]

Originally Posted by aerohead

Automatic transmission vehicles cost less to manufacture than manuals.

You've said that a couple of times. Can you provide a source?

Traditional torque-converter automatic gearboxes are quite complex, what with planetary gearsets and immensely fussy shift valve bodies. Manuals have individual paired gears, and the shifting mechanisms are just sliding forks and rods.

CVTs do seem to be much simpler and probably less expensive to build.

[Isaac Zachary]

Originally Posted by some_other_dave

You've said that a couple of times. Can you provide a source?

Traditional torque-converter automatic gearboxes are quite complex, what with planetary gearsets and immensely fussy shift valve bodies. Manuals have individual paired gears, and the shifting mechanisms are just sliding forks and rods.

CVTs do seem to be much simpler and probably less expensive to build.

From what I understand, the cost to build a car is mostly dependant on how many they can make. It costs money to design, test and make all the production line tools for a car or car part. If they can make and sell a few million the price will be way cheaper than if they make just 3.

The same is likely true of automatics and manuals. Manuals haven't changed much, so I would guess that for the same volume, manuals are actually cheaper. But it makes sense to me that because automatics are so popular and very few buy manual transmissions that it costs more per transmission to make a few manual gear boxes for the 6 and a half people in the USA that like to drive a stick shift than it is to make a hundred thousand automatics for everyone else.

[cRiPpLe_rOoStEr]

CVTs may have a lower production cost, and eventually a more compact size in proportion to the gear-spread, as advantages compared to a more traditional automatic transmission, yet they're not so well-suited to higher torque inputs or heavier vehicles. When it comes to manuals, they still tend to be cheaper to manufacture at least than a traditional automatic. And so are the AMTs, even with the addition of the electronic controls and actuators, and a single clutch is also cheaper than a torque converter, yet it will require a replacement once in a while.

[Isaac Zachary]

Originally Posted by cRiPpLe_rOoStEr

CVTs...
yet they're not so well-suited to higher torque inputs or heavier vehicles.

Unless it's a torodial CVT.

https://www.youtube.com/watch?v=5jIeSgq7ewI

[aerohead]

Originally Posted by some_other_dave

You've said that a couple of times. Can you provide a source?

Traditional torque-converter automatic gearboxes are quite complex, what with planetary gearsets and immensely fussy shift valve bodies. Manuals have individual paired gears, and the shifting mechanisms are just sliding forks and rods.

CVTs do seem to be much simpler and probably less expensive to build.

Bob Lutz ( former CEO of General Motors Corp.) wrote about it in one of his 'Go Lutz Yourself' columns in ROAD & TRACK, or MOTOR TREND.

[cRiPpLe_rOoStEr]

Originally Posted by Isaac Zachary

Unless it's a torodial CVT.

IIRC the only applications for toroidal CVTs were some JDM full-size Nissan sedans.

[Isaac Zachary]

I was looking at the 2022 Toyota Sienna minvan. It gets 36mpg combined and has a CVT of sorts (Toyota's hybrid driveline). Those should be very robust.

[cRiPpLe_rOoStEr]

Toyota's HSD doesn't rely on a CVT properly said, as it relies on the electric motors to emulate the operating principle of a CVT.

[Isaac Zachary]

Originally Posted by cRiPpLe_rOoStEr

Toyota's HSD doesn't rely on a CVT properly said, as it relies on the electric motors to emulate the operating principle of a CVT.

CVEMG: Continuously Variable Electric Motor-Generators.