The AMT or Automated Manual Transmission is an automated gear shifting mechanism that is coupled to a conventional 5 speed gearbox. It is currently available on
Maruti Celerio,
Tata Zest and
Alto-K10 cars in India, and is made by the Italian manufacturer
Magneti Marelli which is a part of the
FIAT S.P.A. group.
Magnetti Marelli describes AMT as follows on their website -
The robotized gearbox is a type of gearbox for automotive use whose name comes from the “robotization”, in other words the substitution of manual drives with automatic drives, of a regular manual gearbox. The electronic control unit independently manages the clutch and gear engagement movements. The Magneti Marelli robotized gearboxes feature hydraulic actuation of the movements, with faster actuation speed and consequently improved sports performances and greater vehicle comfort. Strong of a longstanding experience in this sector, which began with the first robotized gearbox created for the Formula 1, Magneti Marelli supplies its robotized gearboxes to all manufacturers of super sports cars (Ferrari, Maserati, Aston Martin, Lamborghini and Audi), compact cars and commercial vehicles.
So AMT has the pedigree of being born on the Formula-1 race track. Since the mechanical gearbox remains the same, it offers the same fuel efficiency as a manual shifter. I have been driving manual cars for more than 20 years now, and so was very interested in trying AMT out first hand. Here is my experience in driving an AMT Alto-K10 car from Maruti-Suzuki.
The AMT gearbox has two modes, fully automatic mode (D) and manual override mode (M).
Fully Automatic Mode (D)
D mode is for stop and start city traffic. The brake needs to be pressed when you slot the car from Neutral (N) to D. If you keep the brake pressed at standstill in D mode the clutch disengages, and the car remains in first gear. This is exactly like pressing the clutch pedal and slotting into the first gear in a manual gearbox.
When you release the brake, the clutch engages and car starts inching forward, even if you do not touch the accelerator – this is called the
creeping mode, and is useful in stop and start traffic. To get on the move you gradually press the accelerator. The car now picks up speed, and starts shifting to higher gears as it gathers speed.
You can soon learn to coax the AMT by giving the accelerator some respite near it shift points, and it will use the opportunity to upshift immediately for better fuel economy. On the Alto K10 it shifts around 1500 rpm from first to fourth gear at about 10, 20, 35 kmph. It shifts to fifth gear after crossing 50 kmph only.
If your speed reduces, the AMT automatically upshifts as required. If you try to overtake by flooring the accelerator, it responds by upshifting and staying in the same gear for better acceleration. The automated shifting logic actually does its job better than an average driver, so this should result in better clutch life and fuel efficiency.
When you come to a complete halt at a traffic light, it stays in first gear with the clutch disengaged. If the stop is for a long duration above 30 seconds, it is best to engage the handbrake and shift the lever to Neutral (N), to prevent clutch wear. To start going again you have to remember to press the brake, shift to D mode and move on.
If you are on an incline when standstill, you need to use the hand-brake to prevent rolling back. When you release the brake coordination skill of releasing the handbrake and pressing the accelerator in tandem is definitely needed.
When parking the car, it is best to leave it in D mode and shut the engine. This will keep the first gear engaged, and prevent accidental rolling, exactly how we keep the manual gearboxes in gear when shutting down.
Manual Override Mode (M)
This mode is useful when on open highways, when you want to cruise in fifth gear most of the time. I found using D mode on highways causes the AMT box make unnecessary false upshifts to fourth gear. On the highway you can upshift with the flick of the lever when you need to overtake or accelerate. This mode is also useful while climbing and descending hilly roads, as you get to choose the right gear. The AMT in D mode keeps hunting for the right gear under these conditions.
When on the highways in M mode if your speed reduces for some reason AMT will automatically downshift till the right gear for you. You can then upshift using the lever as you accelerate. If you hit a stop light on the M mode, it is best to switch back to D mode. Let the car pick up speed again, and then switch back to M for cruising.
The M mode will satisfy drivers who want to use the power band of their car engine based on the conditions, but will still free them from the hassle of using the manual clutch. This is how the Formula-1 drivers extract the best performance from their cars in racing conditions
. Overall
Overall I feel the AMT transmission is very valuable stress buster in high traffic situations that are increasingly becoming the norm in urban areas. It retains the flexibility of manual override that will appeal to the expert drivers as well. It is a good balance of automation without sacrificing fuel efficiency. The Alto K-10 with AMT and a mix of D and M mode driving on the highway delivered 21 kmpl, which is as good as one can expect with a manual gearbox. AMT is surely capable of becoming the popular choice of automatic transmission in India in the near future.