[volkman10]

Four Years after the introduction of the AMT/ASG by the Nr. 1 Auto leader in India, now the Nr. 2 Player Hyundai joins in with the AMT technology.

Bound to be introduced this month in its new hatch SANTRO, Hyundai will equiq the next set of vehicles with the AMT - the Grand i10 and the Xcent will get it next.

However, AMT-equipped Grand i10s and Xcents are still about a year away as adaptation and testing is yet to begin.

Hyundai chose to develop the system on its own. And the Korean firm believes that the decision to use electrical actuators instead of the more common hydraulic ones is the right one as the solution offers better gear change control and also improved service life

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[arunphilip]

Originally Posted by volkman10

This makes sense - we've seen how many systems have made the shift from hydraulic to electric in the automotive sector (power steering, DSG clutch actuators for some - not all - gearboxes) because electricals are more power efficient, don't require plumbing but just simpler wiring, and require simpler seals (only against dust/water, instead of pressurized fluid).

Good of Hyundai to have taken this step forward, their delay has been well spent.

[giri1.8]

Even though I am not a fan of my Tigor's engine, AMT unit is quiet nice once I understood the shift logic, there is a huge positive for AMT compare to the traditional torque converters, which is engine braking!

Even in Creta review there is a special mention about auto box equipped cars not having enough stopping power.

AMT surely has a bright future if developed more, there are way too many positives than what initial test drive reports suggest.

[Nav-i-gator]

One question for the experts out here:

What is the main difference between a DSG/dual clutch transmission and an AMT, from technical point of view, as both usually use clutch and gear combo, just like a manual transmission.

Isn't it possible (or rather next evolutionary step ) to employ dual clutch system for AMT's as well? After all, AMT just bypass manual intervention and with evolving software (plus electric actuators which would be quicker to execute the command to shift gears), AMT will become more and more responsive.

[arunphilip]

Originally Posted by Nav-i-gator

What is the main difference between a DSG/dual clutch transmission and an AMT, from technical point of view, as both usually use clutch and gear combo, just like a manual transmission.

Isn't it possible (or rather next evolutionary step ) to employ dual clutch system for AMT's as well?

Not an expert, but let me take a stab at it.

DSG transmissions are also automated manual transmissions, and are very similar in concept to AMT, if you look at it:

• They have a specific number of ratios (6 or more), like a manual gearbox, and just as AMTs have (although AMTs start at 4-5 gears). Torque converters and CVTs don't (even though Honda simulates gear ratios in their CVTs).
• Both DSGs and AMTs use friction clutches to decouple the engine from the drivetrain. Torque converters use fluid coupling.
• Like AMTs, DSGs use supplementary power to initiate clutch operation and gear changes - the supplementary power may be electrical or hydraulic.

Where DSGs diverge from AMTs are:

• DSGs are designed and built as one unit from the input shaft to the output shaft. However, AMTs are designed to be retrofitted onto an existing clutch and gearbox design. That's why we find that there are specialist AMT module suppliers (e.g. Magnetti Marelli), whereas DSGs are built up intrinsically by suppliers like Getrag.
• This is not a technical difference, but the price points where AMTs and DSGs are used has resulted in a difference in the amount of cost and effort spent in improving performance and user comfort - DSGs are innately smoother due to their seamless shift nature. Apart from that, there is likely to be much more integration between the PCM (powertrain control module) and the ECU (engine control unit) in a DSG-equipped car, simply because the customers demand more at that price point.
• Again, DSGs are built for tougher loads because they are used as a performance gearbox, and are therefore often coupled with high power/torque engines.

So, to answer your question, if manufacturers take the next step of putting in a second (i.e. dual) clutch on an AMT, we'll end up with a DSG.

[locusjag]

Originally Posted by arunphilip

• They have a specific number of ratios (6 or more), like a manual gearbox, and just as AMTs have (although AMTs start at 4-5 gears). Torque converters and CVTs don't (even though Honda simulates gear ratios in their CVTs).

I have a different understanding. My A-Star Automatic with a torque converter has 4 fixed speeds, 3 of which can be pre-selected and persisted with, if so desired.

I used to own a CVT-equipped compact SUV earlier and my understanding of CVTs is that there are no fixed gears; there is supposed to be electronic wizardry at play to ensure that maximum fuel efficiency is attained by a CVT. If I understand it right, in theory, there are an infinite number of gears in a CVT.


OT: I've also read that CVTs cannot handle excessive torque or Horsepower from an adequately powered engine, which is why CVTs are often seen on smaller cars. And of all manufacturers globally, Nissan is the one who seems to bet big on CVTs, while other manufacturers and their customers are happy with torque converters. Toyota does use the CVT in its smaller Corolla in the US, but doesn't use it in the bigger and powerful Camry.

Meanwhile Nissan has somehow pulled off a CVT in the bigger 300 HP Nissan Maxima somehow...which no other manufacturer has done so far.

[audioholic]

Originally Posted by Nav-i-gator

One question for the experts out here:

What is the main difference between a DSG/dual clutch transmission and an AMT, from technical point of view, as both usually use clutch and gear combo, just like a manual transmission. .

The main difference is the construction of these transmissions. The AMT is just a regular manual transmission with respect to its internals. However, in a DSG, the internal structure is far more complicated, especially around the clutch assembly and the transmission shafts. A DSG transmission by no way is an AMT * 2. It is roughly two transmissions shrunk into one and both work parallely, with the clutch being the decision maker on which transmission provides power and which one prepares for the next gear. Hence, the clutch is a focal point of the transmission as much as the electronics that control various actuators. To know how complex the clutch assembly is, watch this video:

https://www.youtube.com/watch?v=OB4sKKOqqAQ

Compared to this, the clutch assembly of the AMT will typically have a clutch disc, cover and a release bearing.

Beyond this, though the shifting mechanism is similar to a manual gearbox, the actuators are built into the transmission assembly itself compared to the AMT where it sits outside of the gearbox. The controller is again more complex compared to the controller of the AMT with more actuators to control.

[volkman10]

Maruti Suzuki India’s sales of automatics grew at 58% CAGR - considerable chunk of it are from the AMT's.

Maruti offers multiple transmission options, including manual, AGS (auto gear shift), CVT (continuously variable transmission) and AT (automatic transmission). The AGS (or AMT) is available is seven models—the Alto K10, WagonR, Celerio, Swift, Ignis, Vitara Brezza and Dzire—while the CVT is offered in the Baleno, and the AT is offered in the Ciaz and Ertiga

- The company has sold over 5 lakh cars with automatic transmission since 2014.

- In 2018-19, MS sold over 2 lakh cars with the two-pedal, or automatic, transmission.

- Introduced the AGS in the Celerio in 2014, and penetration reached a high 34% in 2018-19.


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[chittybang]

How does an AMT react in stop and start traffic conditions? From what I understand the clutch must be constantly getting engaged and disengaged like any manual transmission car. If so, then is it still better than someone driving a similar manual with unavoidable half clutch at slow traffic? Then wouldn't there be early signs of clutch wear? I am keen to understand if there is a difference in clutch wear between and AMT and manual assuming its a sedate driver in traffic.

[Reinhard]

Originally Posted by chittybang

How does an AMT react in stop and start traffic conditions? From what I understand the clutch must be constantly getting engaged and disengaged like any manual transmission car. If so, then is it still better than someone driving a similar manual with unavoidable half clutch at slow traffic? Then wouldn't there be early signs of clutch wear? I am keen to understand if there is a difference in clutch wear between and AMT and manual assuming its a sedate driver in traffic.

Compared to most "average" drivers out there - AMT does a better job. The clutch bite is well caliberated in most cars (at least the light weight city run-abouts and hatches). So it avoids half-clutch to a great extent. Sedate driving and properly timing brake release works very well.

The creep function itself is tuned so well that unless you release and apply brake for each 1mm gap in front of you, clutch engagement is supreme.
Overall there is no undue throttle input unless the user forces the gas pedal. This ensures very low rpm and less clutch wear. In manual cars - often we see people rev the engine to unnecessary rpms before starting to tentatively release the clutch (due to fear of stalling). This really kills the clutch. Avoided altogether by the AMT.

I have experienced this regularly myself in Alto K10 AMT (my own car) and Tata Tigor XZA (friend's car). Both work very well with the clutch. Don't know about the Renault & Hyundai units' behaviours.

Clutch itself will last very well with this AMT tuning seen in most cars. Whether the automatic actuators themselves last the test of time - too soon to tell yet. Its only been 3-4 years that they are around. So far going good.

[Pancham]

We recently got a Santro AMT in our family and I have a related query.

How do you park an AMT car in an incline? Since it does not come with a 'Park' mode, do we just keep it in neutral and engage the handbrake or do we put it in 'Drive' and shut off the engine? Will the latter cause any damage to the gearbox?

[praveen_v]

Originally Posted by Pancham

We recently got a Santro AMT in our family and I have a related query.

How do you park an AMT car in an incline? Since it does not come with a 'Park' mode, do we just keep it in neutral and engage the handbrake or do we put it in 'Drive' and shut off the engine? Will the latter cause any damage to the gearbox?

Hyundai manual has it described in the Parking section.

When parking on a slope, it is recommended to place the shift lever in D (Drive) for uphill and R (Reverse) for downhill and to engage the parking brake before turning off the engine. If the engine was turned off with the shift lever in D (Drive) or R (Reverse) position, it is necessary to depress the brake pedal and move the shift lever to N (Neutral) position to turn on the engine

The transmission is identical to the manual unit and hence you can keep it in D/R as applicable just like how we move the lever to 1st or R in manual when parking. One requirement is to do it before you switch off the engine in this case since the shifts may not happen with AMT if engine is switched off.

Also one more titbit found in the manual.

During the first 1,500 km (1,000 miles), you may feel that the vehicle may not be smooth when accelerating at low speed. During this break-in period, the shift quality and performance of your new vehicle is continuously optimized

Mods, Please merge this with my post above.

[Pancham]

Originally Posted by praveen_v

Hyundai manual has it described in the Parking section.

The transmission is identical to the manual unit and hence you can keep it in D/R as applicable just like how we move the lever to 1st or R in manual when parking. One requirement is to do it before you switch off the engine in this case since the shifts may not happen with AMT if engine is switched off.



Also one more titbit found in the manual.



Mods, Please merge this with my post above.

This is super useful. Thanks a lot Praveen.

[volkman10]

With Over 6 Lakh Automatic Cars sold, Maruti Suzuki bets big on AMT, AT & CVT Technology.

Maruti Suzuki’s automatic vehicles are popular across the country, particularly in markets like Bangalore,Delhi, Hyderabad, Mumbai, Pune and Chennai.

The Company offers automatic options in 12 models and a choice of three different automatic transmissions – Auto Gear Shift (AGS), Automatic Transmission (AT) and Continuous Variable Transmission (CVT). The AGS is offered in Alto K-10, S-Presso, WagonR, Celerio, Ignis, Swift, Dzire and Vitara Brezza. The AT transmission is offered in Ertiga, Ciaz and XL6 while Baleno comes equipped with CVT technology.

Source: Maruti Suzuki

[volkman10]

Automatic car sales rise in India: Courtesy Maruti Suzuki, launching the Celerio with AMT at a price gap was about Rs 45,000 — nudging the buyer towards trying out this technology.

From a mere 2-3% a few years ago, automatic gearbox cars now form about 20% of the market.
Women buyers and senior citizens increasingly prefer automatic cars. Lastly, the penetration levels of automatic cars are so low in India that these have to increase

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