Every day we are making some tough calls. Choosing a perfect car among so many choices is hectic and what if you have to choose again which engine and transmission. Here, we can’t gamble because we are investing huge capital and why do we have to do so if we could decide straightforward. Most of us are very clear about engines, either to buy gasoline or diesel. And in case you are confused about naturally aspirated engines or Turbocharged, look at my last blog.
Now let’s talk about transmissions.
First: why we need a transmission in our vehicle. It transfers engine power to the driveshaft and the wheels, maintaining different gear ratios for higher speed at lower RPM.
In the absence of transmission—i.e. direct power transfer to wheels—the top speed obtained will be nearly 20-30 kph at 6000-7000 RPM.
At higher RPM, fuel consumption is more; heat dissipation is greatest, and engine life reduces vigorously. So to get a higher speed at lower RPM, some changes have to be done and the transmission is a device that governs these changes by changing the gear ratio. When we shift the gear from 1-2-3-4-5-6, the vehicle speed continues the same, but engine RPM reduces, so again, we can increase the Engine RPM up to threshold RPM by accelerating to increase the speed of our vehicle.
The industry is trying to make things easier for the users; they are opening lots of options. Today, we have manual, semi-automatic, and fully automatic transmissions available in the market. But most of us are confused about which one is best for us. No doubt all the transmissions are good, but a comparison is to help the users.
Manual Transmission is the oldest and the simplest transmission in the market, but it doesn’t mean it is outdated and needs a replacement. This transmission allows us to shift the gear by ourselves, so they provide the best acceleration and the thrust many young drivers love. Moreover, they offer the best fuel efficiency, good life span, reliability, lowest maintainable cost.
For the betterment of users, some elements have been subtracted from the manual transmission and automated devices are installed. Transmissions like IMT, AMT, and CVT are welcomed wholeheartedly by the customers as they make the drive easy and effortless.
IMT- (intelligent manual transmission) is a clutchless manual transmission. This technology is designed in a way that we have a knob to shift the gears similarly as in manual transmission, but we need not press the clutch; so the clutch is not given. When we try to shift the gear, the sensors sense it and disengages the crankshaft and the driveshaft (very like the clutch assembly). This technology is beneficial in heavy traffic and in cities as we don’t need to clutch again and again as it is painful and hectic sometimes. The technology is around 25-30 thousand costly than the manual transmission. The involvement of some electronic devices, like sensors and actuators, may need some maintenance after 5-7 years.
CVT- (continuously variable transmission) is entirely different, which offers gear-less transmission. No clutch assembly is required. The crankshaft shaft and driveshaft are arranged with a belt and when speed increases due to centrifugal forces, the ratio changes automatically and continuously. In an automatic transmission, when a gear shifts, we feel a jerk, which will not be felt in CVTs. There is a lag at the early stage. When we accelerate the vehicle from zero, it takes time to speed up. The overall performance is very nice, but we miss a powerful start here.
AMT- (automatic manual transmission) or auto-gear shift, is a manual transmission only, but with a small mind, i.e. ECU. ECU has coding which tells the vehicle in which gear the vehicle should be in at a particular speed, or paddle pressure, etc. This transmission gives us two options either select manual and upshift or downshift the gears or select automatically. In this case, we just have to accelerate—the actuators will automatically engage and disengage the clutch and shifts the gear. No doubt it is reliable and has the same manufacturing technology as the manual transmission, so it is lightweight compared to fully automatic. It costs around 50-70 thousand more than the manual, but it is the cheapest automatic transmission. The gear shift is very laggy and not smooth, which jerks while shifts is the only problem with this transmission. But overall performance is very nice and buying-worthy.
DCT/DSG- (dual-clutch transmission/ direct-shift gearbox) is what we generally call fully automatic. This transmission has dual-clutch technology. The odd gears, i.e. 1,3,5,7, are attached to one clutch, and even gears, i.e. 2,4,6, are attached to another clutch. This automated gearbox is very fast and smooth compared to AMT. Also, we won’t feel any lag during gear shifts because of dual-clutch technology. When a gear shift is required, clutch one disengages, and the clutch two engages simultaneously, so the time gap is very small. Though this is the most expensive transmission, which costs around 1- 1.5 lakhs more than a manual transmission. But comfort and luxury always demand more. We need not clutch and gear our vehicle again and again. DCT has a good life span, very reliable, but it is costly, demands high maintenance, and offers approx 10% less mileage than the manual one.
In Conclusion:
Every Transmission is good on its own. The goal is to choose one which fulfils our requirements. Manual is best for its low cost, simple design, and good mileage. Prefer IMT if you don’t want to clutch again and again, but won’t the feel of manual. Opt for AMT if want to buy an automated vehicle but have budget problems. If not, DCT is the best choice. In case you want to try something different, buy CVT
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