The CVT craze

As Indians increasingly move down the automatic route, some carmakers are preferring to incorporate CVT gearboxes. But what are Continuously Variable Transmissions and how are they different?

A decade ago, there were few options if you wanted to buy a small automatic hatchback or small sedan. Maruti had a four-speed on the Dzire, Hyundai had a similar box on the i10 and i20. Of course, when it came to premium cars, finding one with a manual transmission was the hard thing, but small cars manufacturers on the whole avoided putting automatic transmissions in cars below the 10-lakh mark because they felt Indian consumers were not used to automatics and would not want to pay the premium for one. This was evident ever since the first small automatics I drove in India, a three-speed WagonR automatic and a Santro Automatic. They were both lovely small cars to drive but the dual problems of reduced fuel economy and the cost of a traditional torque-converter automatic made automatic hatchbacks dead on arrival a decade ago.

Automatic variants were launched now and then — the first-generation Hyundai i20 and the much-maligned Maruti-Suzuki A-Star both came with automatic variants. But it took the arrival of a low-cost automatic transmission, the Automated Manual Transmission (AMT) marketed by Maruti as Auto Gear Shift (AGS) on the Celerio that changed market perceptions. The Celerio was followed into the market by a whole host of AMT-equipped vehicles, not just from Maruti. You had the Alto K10, the Dzire and now the Brezza with AMT, Renault also brought in the Kwid and Duster equipped with AMT boxes as did Tata on their new cars with the Nexon being the latest addition. AMTs are cheap and cheerful transmissions according to the carmakers, because they remove the clutch pedal, although not the clutch. The way an AMT works is having a mechanical servo motor operate the clutch pedal. This motor is controlled by a computer that evaluates your foot position on the accelerator and changes gear accordingly. Having driven several AMT cars, it becomes apparent that one has to adjust their acceleration style in order to change gears. Also, AMTs being regular manual transmissions are not what one would call “advanced technology” and they tend to be a bit lazy when shifting gears, so you have this feeling that you yourself could do it faster. As good as the implementation of AMT gearboxes have become, there is also what one calls “shift shock”, that is the juddering of the car when you shift gears. This is minimal in most new AMT-equipped cars, but still palpable.

This brings us to Continuously-Variable Transmissions (CVT) which are becoming increasingly popular in slightly more expensive small cars and sedans. Honda had a CVT transmission in the third-generation City and carried it onto the new City. Maruti launched the Baleno with a CVT option, and now both Honda and Toyota have given CVT options on their latest products, the Amaze and Yaris respectively. Honda even introduced a segment-first diesel CVT with the Amaze which was reviewed in this column last week. And now, Hyundai has also entered the CVT game, equipping the i20 Elite with a CVT, a vehicle that I drove extensively around Delhi over the past week.

Now, in an ideal world a CVT, as its name suggests, should be the perfect transmission as the power from the engine is translated perfectly to the wheels. Of course, we do not live in a perfect world. Cars need to constantly accelerate and brake, negotiate traffic and face wildly different road surfaces. So all CVT transmissions have pre-programmed “steps” in them like gears — the i20 CVT for example has six “steps.” The problem with a CVT is what is known as the “rubber-band” effect. It is known as such as the power is transferred from the engines to the wheels using bands, but its impact is noticeable on the rev-counter. You notice the engine revs often go up and down the range as the car tries to figure out what gear is the best. Of course, some vehicles let you override this through either a shifter on the gear lever, or in some cases a paddle-shifter on the steering wheel.

But, at the same time CVTs are far superior to AMT transmissions when it comes to the aforementioned “shift shock.” You can figure out that the car might have gone up or down a step by hearing the engine note, but inside the vehicle there is no sensation at all that you have changed gear. As such, the CVT does feel almost continuous, it is indeed extremely comfortable. Now, personally, the traditional torque-converter automatic transmission or the newer dual-clutch transmissions offered up the price range are far superior even to a CVT as they can deal with more power and weigh a bit less, but CVTs are a cost-effective and modern solution for those who want automatics.

Now to the i20 Elite CVT, it suffers from a couple of issues that I feel most CVTs and to an extent even AMT cars have. These are not transmissions designed for exhilarating performance. Hyundai’s 1.2 VTVT petrol engine is quite peppy but compared to the CVT it feels very leisurely. This has possibly been done to keep fuel-economy in check since the car delivered, as per its own computer 9.7 km per litre, about 2 km per km less than a regular manual I would guess. The story is pretty much similar on Maruti’s Baleno CVT, which also feels sluggish and is not a car that you would want to gun down a highway. The CVT is ideal for a crowded city and delivers a great and painless ride, at the cost of some fuel.

Then again, Hyundai has been able to mate the CVT to the smaller 1.2 litre petrol engine, unlike the four-speed torque-converter automatic they had on the previous generation i20. And with some running in, I had a brand-new car after all, fuel economy should also improve slightly. The CVT is available on the Elite i20 on the Magna and Asta trims for Rs 7.04 lakh and Rs 8.16 lakh respectively, about a lakh more than the manual variants. These prices make the i20 CVT cheaper than comparable Maruti Baleno and Honda Jazz variants equipped with CVT boxes. The rush of CVT installations should also see such transmissions being manufactured in India, which should also have a positive impact on costs going forward.

Would I get a CVT if I wanted to have some fun? Probably not, given that Volkswagen offers the fantastic dual-clutch gearbox on the Golf, Ameo and Vento. But you don’t see people rushing to buy a VW right now. In the next few years, it is almost certain that more CVT gearboxes will be offered across cars in India, small and big.