Introduction
There was a time when the automatic gearbox was pretty much the least preferred option in the Indian automotive market. They were considered too heavy on main tenance, guzzled a lot more fuel, ate up brake pads and were considerably more expensive to buy than their manual variants. However, those were also the days when you could get from point A to B in far lesser time than you can imagine now. With congestion on an all-time high, traffic conditions are pretty much as bad as they can be. It is a time when your left leg is gaining a lot more muscle than the right one and the clutch pedal is working overtime. Now manufacturers have understood that automatic transmissions are the need of the hour and as a result you have automatic variants across all segments with sales on the rise as well. Now there are different types of technologies when it comes to Automatics. While their most common function is to provide respite to the left leg, they differ from each other like chalk and cheese. We at CarWale decided to ease out this dilemma in a bid to help you find the automatic transmission of your choice.
Choosing the right automatic gearbox
Torque Converter
Now this is the oldest of the bunch and was the most commonly used AT technology until recently. As of today, pretty much the entire Hyundai line-up like the i10 Grand, i20 Elite Verna and the likes use a torque converter. Instead of using a clutch to engage and disengage the engine's torque from the gearbox, traditional autos keep the drivetrain connected at all times by using a torque converter. This slightly complex bit of engineering pushes fluid around a sealed case using something called an impeller. The fluid drives a turbine on the other side of the case, which sends drive to the gearbox.
Torque-converter automatics have the clear advantage of big torque at low revs, which is great for acceleration off the line and overtaking. Acceleration from a standing start is smooth, as are the gear changes however, one traditional problem with torque converters was that they are essentially inefficient which usually means larger than usual fuel bills.
AMT – Automated manual transmission
AMT is by far the most trending gearbox s of today and not without a reason. Pretty much every manufacturer have resorted to using it. Starting from Maruti who started the AMT trend in the Alto, Celerio, Wagon-R and the Dzire. Tata used it in the Zest and the Nano while Renault plonked it in the new facelifted Duster. Mahindra decided to join the bandwagon too and used it in the TUV 3OO and the Nuvosport.
In case you’re wondering how so many cars incorporate the AMT transmission, it’s because it doesn't replace the manual transmission, unlike the automatic transmission system, which is entirely different. The AMT is just a kit that can be added to any manual transmission, however it has to be factory fitted. This transmission utilises several key parts, which are not found in a manual transmission, in order to work properly. These include the torque converter, valve body, pump, and clutch bands.
The biggest advantage with the AMT besides putting your left leg at ease is that it can be more fuel efficient than a manual gearbox should you treat it well, but AMT s take a long time to disengage the clutch, change gears and re-engage, making them jerky and annoying, especially at low speeds. But the technology is still evolving and is sure to get more refined and popular over the years. In fact, industry experts predict that 20 per cent of the passenger vehicles sold in India will have AMT by 2020.
CVT – Continuously Variable Transmission
This is another gearbox which has been around for a while now. We have had it in cars like the Mitsubishi Outlander, the Nissan Teana and then some. As of now Honda uses the CVT in the CR-V and the City and is sure to plonk it in the new Accord as well. In the hatches you have Maruti following suit with the popular Baleno getting a CVT transmission. Nissan has been using the same in the Sunny and the Micra for a while now.
So a CVT does exactly what it says on the label. Instead of swapping through a set number of pre-determined gears, a CVT can vary its drive ratios on the fly, almost infinitely. Now CVT s can be quite frugal and pretty much the smoothest of the lot when it comes to shifting. However, it does get plagued by the rubber-band effect wherein the revs rise quickly as you floor the accelerator but the actual acceleration does take a while. CVT s are tried and tested and will remain one of the popular choices.
DCT – Dual Clutch Transmission
Now this is the mother load as far as automatic transmissions go. Volkwagen, Skoda, Audi, Porsche, Mercedes-Benz and BMW are the ones that swear by twin clutch transmissions. VW of course, offers it on a more mass market level in cars like the Polo and the Vento.
One of the main USP of this gearbox is lightning quick shifts which is faster than anything out there and is fuel efficient at the same time. The DCT works in a similar fashion to a manual transmission except that there are two separate gear sets and the shifting is computer controlled. More importantly, the two clutches operate different gears, which allows for gear changes to happen without disconnecting the engine from the transmission and interrupting power flow.
The only downside we see to a DCT is that when it does have a problem, it could end up being a costly affair, but then most gearboxes offered by manufacturers are pretty reliable. So if you want the best of both worlds, performance like a manual and the convenience of an AT, it does not get better than DCT’s.
With plenty of technology available for gearboxes and it being affordable as well, automatics definitely have a bright future ahead. Looking at a few statistics, half of all Innova Crysta, 20 per cent of Hyundai Creta and 32 per cent of Honda Jazz cars sold are automatics. Even at the budget end, 20 per cent of Maruti WagonR and Alto, and 44 per cent of Maruti Celerio cars have autoboxes. In fact, in 2015, nearly 262,500 passenger cars equipped with AT were sold in India and this shows a change in mindset from price and fuel economy to convenience. Hope this article helps you choose the right automatic car and join ‘save the left leg’ revolution!
