Editing Semi-automatic transmission (section)

=== Automated manual transmissions ===
{{main|Automated manual transmission}}
[[File:Paddle Shifter Honda Accord 2013.JPG|thumb|Paddle shifter on a car.]]
Starting in the late 1990s, automotive manufacturers introduced what is now called an [[automated manual transmission]] (AMT), which is mechanically similar to, and has its roots in, earlier clutchless manual transmission systems. An AMT functions in the same way as older semi-automatic and clutchless manual transmissions, but with two exceptions; it is able to both operate the clutch and shift automatically, and does not use a torque converter. Shifting is done either automatically from a [[transmission control unit]] (TCU), or manually from either the shift knob or shift paddles mounted behind the steering wheel. AMTs combine the fuel efficiency of manual transmissions with the shifting ease of automatic transmissions. Their biggest disadvantage is poor shifting comfort due to the mechanical clutch being disengaged by the TCU, which is easily noticeable as "jolting".{{Citation needed|date=October 2021}} Some transmission makers have tried solving this issue by using oversized synchronizer rings and not fully opening the clutch during shifting—which works in theory, but as of 2007, there have not been any series production cars with such functions.{{Update inline|date=October 2021}} In passenger cars, modern AMTs generally have six speeds (though some have seven) and a rather long gearing. In combination with a smart-shifting program, this can significantly reduce fuel consumption. In general, there are two types of AMTs: integrated AMTs and add-on AMTs. Integrated AMTs were designed to be dedicated AMTs, whereas add-on AMTs are conversions of standard manual transmissions into AMTs.{{Citation needed|date=October 2021}}

An automated manual transmission may include a fully automatic mode where the driver does not need to change gears at all.<ref name="x-engineer1">{{cite web |url=https://x-engineer.org/automotive-engineering/drivetrain/transmissions/automated-manual-transmissions-amt/ |title=Automated Manual Transmission (AMT) |website=x-engineer.org |access-date=2020-02-29 }}</ref> These transmissions can be described as a standard manual transmission with an automated clutch and automated gear shift control, allowing them to operate in the same manner as traditional automatic transmissions. The TCU automatically shifts gears if, for example, the engine is [[redline]]d. The AMT can be switched to a clutchless manual mode wherein one can upshift or downshift using a [[Center console (automobile)|console]]-mounted shift selector or paddle shifters.<ref>{{cite news|last=Woodyard|first=Chris|title=Among bells and whistles, cars shift to buttons, knobs|url= https://www.usatoday.com/story/money/cars/2014/08/10/cars-shifting-knobs-buttons/13721433/|access-date=2021-10-15|website=USA Today|language=en-US}}</ref> It has a lower cost than conventional automatic transmissions.<ref name="zf1">{{cite web |url=https://www.zf.com/products/en/cars/products_29280.html |title=Automated Manual Transmission |website=zf.com |access-date=2020-02-29 |archive-date=26 September 2020 |archive-url=https://web.archive.org/web/20200926015226/https://www.zf.com/products/en/cars/products_29280.html |url-status=dead }}</ref>

The automated manual transmission (trade names include ''SMG-III'') is not to be confused with "[[manumatic]]" automatic transmission (marketed under trade names such as ''Tiptronic'', ''Steptronic'', ''Sportmatic'', and ''[[Geartronic]]''). While these systems seem superficially similar, a manumatic uses a torque converter like an automatic transmission, instead of the clutch used in the automated manual transmission. An automated manual can give the driver full control of the gear selection, whereas a manumatic will deny a gear change request that would result in the engine stalling (from too few [[RPM]]) or over-revving.<ref name="x-engineer1" /> The automatic mode of an automated manual transmission at low or frequent stop start speeds is less smooth than that of manumatics and other automatic transmissions.<ref>{{cite web|url=http://www.leftlanenews.com/review-m5s-smg-sucks-all-the-joy-from-experience.html|title=Review: M5's SMG "sucks all the joy" from experience |website=leftlanenews.com |access-date= 24 March 2019}}</ref>