Toyota MMT 'automatic'

Toyota's MMT, as far as I understand, has a sequential gearbox, a bit like a motorbike's, which goes up a gear or down a gear, one at a time, coupled to a conventional clutch.

It's a lot more like a robotised manual transmission than a conventional "automatic" which has a torque convertor etc.

Instead of your brain telling your leg to operate the clutch and your arm to operate the gearlever based on what you know about what revs the engine is doing and how fast you want to go (like on a normal manual car), there's a computer and some electromechanical/hydraulic gubbins doing all this clutch in, clutch out/up a gear, down a gear stuff for you.

The only such system I have tried was in a Smart ForTwo and a Smart Roadster, possibly among the first widely available examples of such a system.

It is very confusing not least because different names are sometimes given to the same technology. Essentially there are three major kinds of transmissions transferring power from the driving axle of the engine to the driven axle of the wheels: (1) Direct contact, metal to metal - the traditional manual transmission; (2) Indirect via fluid which turns rigid (torque converter) - automatic transmission; and (3) Indirect contact via a belt - Continuously Variable Transmission.

There is a new* category which conceptually can be placed between (1) and (2), a large assorted group some of which are in fact modified (1) and others are modified (2), yet some others are combination of (1) and (2). The best description I have is this short article:

a more or less complete list of the alternative names of the same (2),read under "Tiptronic", 1/2 down the page: "Clutchless manual transmission" is a bad name for clutch(paddle)less is the common characteristic of them all. In my mind, these are recognized as: (a) Manual transmission with robotized clutch (Here is how-it-works); (b) Manual/automatic transmission with robotized clutch and gear shift; and (c) Dual Clutch Transmission**.

To demonstrate just how confusing it is, the MMT in Toyota Corolla is (a), but the identical name, MMT, in Toyota MR2 is (b).

*Not that new, some appeared in the 50's. **A better explanation with animation:

That explanation is slightly confusing. It suggests the only type of synchromesh automatic transmission is the dual clutch type - but it's not. The BMW SMG - which has an auto mode - is still single clutch.

The twin clutch type is much superior, though. Until it goes wrong...;-)

Thanks to everyone who has replied - very helpful information. Thanks again John

Correction: The MMT in Toyota Yaris is (a), while the MMT in Toyota Corolla and MR2 is (b) -- equivalence in Vauxhall Corsa's Easytronic, and Renault Clio's Quickshift.