Automated manual transmission: how it works, why it interrupts drive and what to expect from a used one

• An automated manual transmission is an ordinary manual gearbox with a single clutch. Instead of the driver, electronically controlled actuators, either electric or hydraulic, operate the clutch and the gearchanges.
• Every time it changes gear, the clutch disengages and drive drops out for a moment. That is where the typical "head nod" of the occupants comes from. You can soften it by easing off the accelerator as the gearbox shifts, or by using manual mode.
• On the used market you will find it mainly in small cars, under names such as ASG (Volkswagen up!, Škoda Citigo), x-shift (Toyota Aygo), Dualogic (Fiat 500, Fiat Panda), Easytronic (Opel Corsa) and ETG (Peugeot 208, Citroën C3).
• On a used car, both the clutch and the actuators wear. Town driving with frequent pull-aways takes more out of them than the odometer reading suggests.
• Anyone who expects smooth pull-aways and jerk-free gearchanges from an automatic will be happier with a dual-clutch gearbox, a CVT or a torque converter automatic.

The automated manual transmission appears mainly in older small cars. For manufacturers it was a cheap way of offering driving without a clutch pedal. In listings it is also called a robotised manual, semi-automatic or AMT. The driver only selects the direction of travel, accelerates and brakes, so from the driver's point of view it is an automatic. Do not expect the smoothness familiar from other automatic gearboxes, though. For how the other designs differ, see our overview of types of automatic transmission.

It is based on an ordinary mechanical gearbox with fixed gears. In typical small cars it is paired with a single dry friction clutch. The only difference from a manual is how it is operated: the work of the driver's left foot and right hand is taken over by actuators. They work electrically or with the help of hydraulics.

The control unit decides when to shift based on road speed, engine load and accelerator position. The gearchange itself then happens just as in a manual:

1. Engine torque is reduced and the clutch disengages.
2. The shift mechanism takes the current gear out and selects the next one.
3. The clutch re-engages and power flows to the wheels again.

The electronics have to synchronise engine speed, clutch movement and the shift mechanism. How quickly and smoothly the gearchange happens depends on how well they are calibrated. The essence does not change, though: there is a gap in drive during every gearchange.

This is where an automated manual differs from a dual-clutch DSG. The DSG has two clutches, one for the odd and one for the even gears, so the second takes over the drive before the first disengages. An automated manual has only one clutch, and during a gearchange there is nothing to stand in for it.

When accelerating, the engine pulls the car forward. As soon as the gearbox disengages the clutch, acceleration eases off for a moment and the occupants lurch forward. When the clutch re-engages, drive returns and heads go back. It is most noticeable under hard acceleration and when changing between the lower gears.

A short pause that is always the same is part of the design. Thumps, pronounced judder when pulling away or loss of drive, however, are not "normal behaviour for an automated manual". They point to a worn clutch or problems with how it is operated.

Driving an automated manual is similar to driving a manual. When you expect a gearchange, ease off the accelerator slightly and the interruption in drive will be gentler. In manual mode you can time your shifts yourself before a bend or a climb, but the electronics still take care of the clutch.

Each manufacturer used its own trade name. On small European cars that are commonly sold used, you will mainly come across these names:

The generic term for the design is AMT (Automated Manual Transmission). The word "automatic" in a listing does not tell you the gearbox type. On top of that, the same model may have had a completely different gearbox depending on generation and engine. So rely on the gearbox's trade name in the technical details of the specific car. The model alone will not tell you the gearbox type.

Automation made use of an existing manual gearbox and simply added self-operating controls. This let manufacturers offer a small car without a clutch pedal without having to develop a more expensive design.

Its weak point was comfort. People expect continuous drive from an automatic, but the automated manual kept the pauses familiar from a manual. Meanwhile, dual-clutch gearboxes and CVTs became cheaper and found their way into small cars too. Hybrid powertrains also brought their own solutions. The automated manual's main advantage, its low cost, therefore lost its point.

As a result, conventional single-clutch automated manuals have all but disappeared from new European passenger cars. Among used small cars, however, they remain common.

Wear comes from two directions here: from the mechanicals carried over from the manual and from the controls that operate them. The clutch is a wear item. Its condition depends mainly on how the car has been driven so far. Pulling away, parking and creeping in traffic jams strain it far more than motorway driving.

Besides the clutch, the actuator and its electric or hydraulic controls may also need repair. After replacing the clutch or an actuator, the system also has to be taught the new positions and the clutch bite point. Replacing the part, then, does not complete the repair.

Low mileage does not guarantee the gearbox is in good condition. A small city car may have thousands of pull-aways behind it even though it has covered few kilometres. Conversely, the characteristic pause during gearchanges tells you nothing about how much life the clutch has left. On a test drive, it is worth pulling away from standstill several times, including uphill. Pulling away should be smooth, without jerking and without an unusual rise in revs. A detailed checklist is in our article on buying a used automatic car.

An automated manual is a compromise that makes sense if you accept it knowingly: it frees you from the clutch pedal, but the interruptions in drive remain. Anyone who expects smooth pull-aways and seamless gearchanges from an automatic will do better with a different type of gearbox. In small and compact cars that tends to be a dual-clutch gearbox or a CVT; in larger cars, a torque converter automatic.

Carvago has the widest selection of used cars, with around a million vehicles from dealers in several European countries. So even among small city cars you can easily find the same model with a different type of automatic. If an automated manual suits you, you can choose a well-kept example from among the offers.

Before sale, every car is inspected by a technician as part of CarAudit™, which covers up to 270 checkpoints. The inspection includes a check of the technical components, diagnostics and a test drive. You know the result before you decide to buy the car, and Carvago guarantees the condition stated in the CarAudit™ certificate. Every car comes with a free extended warranty.

Before sale, Carvago buys the car from the original seller and takes on its risks, so you buy directly from Carvago. Under a power of attorney, Carvago arranges registration of the car in your country, including the paperwork, and as standard delivers it to your door. You can drive off as soon as you take it over.

Is a "sequential gearbox" the same as an automated manual?

No. Sequential means that the gears are selected one after another in order. In listings, sellers sometimes use the term for the manual mode of any automatic. It tells you nothing about the number of clutches or how power is transmitted.

Why is there no P position on an automated manual's selector?

Many automated manuals have no parking pawl of the kind you know from other automatics. It is not missing equipment or a fault. When parked, the car is held by the parking brake or by having a gear engaged.

Does a car with an automated manual use more fuel than a manual?

Usually not. The mechanicals and the losses in the gearbox are the same as in a manual, so the official fuel consumption figures for both versions tend to be identical or very close. Higher consumption is more typical of older torque converter automatics than of automated manuals.

When does an automated manual make sense?

It suits a driver who wants a small car without a clutch pedal and can live with the pause in drive during gearchanges. Typically that means short town journeys and relaxed driving. Anyone who spends a lot of time in traffic jams or wants smooth comfort will be happier with a different type of automatic.

1. https://www.fiat-lancia.org.rs/Manuals/other/Nuova_Bravo/100012408.pdf
2. https://newsroom.toyota.eu/2019-new-2014-aygo/
3. https://uploads.vw-mms.de/system/production/files/vwn/003/768/file/e451eac3067123ff305d27a85f3e7eb73dd1ee6f/DSG_the_intelligent_automatic_gearbox_from_Volkswagen_2008_en.pdf?1530367024=
4. https://www.topgear.com/car-reviews/volkswagen/hatchback-2012/10-high-5dr-asg/first-drive
5. https://carvago.com/car-delivery
6. https://carvago.com/caraudit
7. https://carvago.com/how-carvago-works