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Comment by dhd415 | Hacker News Reader

In terms of technological advances, the automatic transmission is a tenuous improvement over the manual transmission. It costs more to manufacture and service and it performs less well (transfers engine torque less efficiently to wheels and cannot anticipate the need to upshift or downshift) in exchange for requiring less skill from drivers. The newer sequential manual transmissions (SMGs) blend the benefits of both with the mechanics of a manual transmission but shifts performed electronically. They're great except that they cost even more. I, for one, am happy with my old, reliable manual transmission.

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My understanding is that while it used to be true that manual transmissions were more efficient due to humans keeping the engine in the torque sweet spot, it's no longer true since automatics can have so many more gears than manuals. And that's not even considering something like a CVT, which I understand can be even more efficient.

You're right about more gears in auto transmissions helping to keep the engine at its ideal RPM for torque. There are still more mechanical losses in an auto transmissions since the auto transmission's fluid-based torque converter does not transfer engine rotation as efficiently as a manual transmission's friction-based clutch when the latter is fully engaged.

Can confirm what the other commenter was saying, lockup torque converters exist. Most of the complaints you have are about 90s era auto tech which suuuck hard.

Example, 08 bmw I had with a ZF 6 speed auto. Pain to drive taking off cold in the morning as the software would allow it to slip. Functioned as an old school auto. Normally however, kick it from the line, it would hook up. This was a car with 500+ lbft of torque.

A little software mod and it was probably better to drive (with the paddles) than a manual in terms of engagement. Also let you keep both feet on the control peddals to modulate around the track.

Could also drive this thing for 6-7 hours, arrive and not feel tired.

Modern auto transmissions have an integrated clutch which engages once the input/output shaft speeds line up. The feature is called "lock-up".

> cannot anticipate the need to upshift or downshift

I feel like this is a red herring. How often does the computer fail to correctly upshift or downshift in such a way that it affects, say... mileage?

I find that when I drive my vehicle (an automatic transmission Mazda CX5), if I am using the "fake manual" (tiptronic), I tend to drive at a slightly higher rpm. I will sit at 2¼k rpms instead of the computer's preferable 1¾k rpms. I can assume from that that I am indeed burning more fuel (if only marginally)

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