Torque Converter automatic for petrol engines

CarML · 11th July 2021, 22:11

Most of the popular recent crossovers or mid-size SUVs, be it Korean or German (read Seltos, Creta, Kushaq, et al) offer turbo petrol with CVT/IVT or DCT/DSG gearbox. Only their Diesel engines are mated to Torque Converter AT. I have seen only Vitara Brezza and Ford Ecosport offering Torque Converter AT with their petrol engines. I wonder why!
Enough has been said and written about reliability issues of DCT/DSG gearbox. They also command a premium price over all other automatic transmission options. Torque Converters are supposed to offer smooth gear-shifts, while being far more reliable in the long term. So, why can't the Koreans, for example, provide 1.4L turbo petrol with Torque Converter AT as an option?

Shreyas_H · 11th July 2021, 23:08

The new Polo/Vento/Rapid/Kushaq/Taigun 1 L TSI is mated to a slick Torque converter box.

The new alcazar also comes with a Torque converter with the 2L petrol engine.

Torque converter boxes typically are lesser economical in fuel consumption, possibly why some manufacturers would hesitate to pair them with Petrols.

BeantownThinker · 11th July 2021, 23:23

I drive a Korean Petrol Automatic with a TC transmission. So you see these "mythical" creatures do exist.

In the current market, I think, the Maruti Ciaz continues to offer a petrol automatic with a 4-speed TC AT.

Before the advent of AMT/IMT/DCT/DSG, etc most of the petrol automatics had been TC transmissions. Hondas have conventionally been CVTs from as far back as I can remember.
Hyundais of the past have also relied on TC transmission. It is only off-late that they have moved to DCT and IVT for their petrol engines.

Now to the question as to why they have moved. The answer is simple. TC gearboxes are the most reliable BUT the most thirsty of gearboxes amongst all the auto transmissions. I drive a Verna petrol TC AT and get about 7.0 to 7.5 kmpl in the city and about 11.0kmpl on the highway fully loaded.

From my experience when it comes to fuel efficiency it goes likes this for petrol engines Manual > CVT/IVT > IMT/AMT > DCT/DSG > TC. This is the reason why many TC gearboxes on petrol engines have been replaced with CVT or DCT. i10 has moved from TC to AMT and the i20/Verna/Creta have also moved from TC to IVT/DCT/IMT

TrackDay · 11th July 2021, 23:39

I guess the Dual clutch gearboxes are provided for those who would like a more sporty performance with faster gearchanges. However I agree there have been issues with them, though some owners have managed to go on without any problems.

The torque convertor is the oldest automatic going by general implementation if I am not wrong. The evolution has seen manufacturers go to other gearboxes and finally completing a full circle, returning to the trusty torque convertor. One point that is raised about them is the mileage and I guess this is why the Ciaz & Brezza have some mild hybrid in their automatics. How much mileage do the EcoSport, Rapid automatic (TC) owners manage to get from their cars ?

11th July 2021, 22:11	#1
CarML BHPian Join Date: Jul 2021 Location: Bangalore Posts: 41 Thanked: 104 Times	Torque Converter automatic for petrol engines Most of the popular recent crossovers or mid-size SUVs, be it Korean or German (read Seltos, Creta, Kushaq, et al) offer turbo petrol with CVT/IVT or DCT/DSG gearbox. Only their Diesel engines are mated to Torque Converter AT. I have seen only Vitara Brezza and Ford Ecosport offering Torque Converter AT with their petrol engines. I wonder why! Enough has been said and written about reliability issues of DCT/DSG gearbox. They also command a premium price over all other automatic transmission options. Torque Converters are supposed to offer smooth gear-shifts, while being far more reliable in the long term. So, why can't the Koreans, for example, provide 1.4L turbo petrol with Torque Converter AT as an option?
	() Thanks

11th July 2021, 23:08	#2
Shreyas_H BHPian Join Date: Feb 2019 Location: Mumbai Posts: 358 Thanked: 1,785 Times	Re: Torque Converter automatic for petrol engines The new Polo/Vento/Rapid/Kushaq/Taigun 1 L TSI is mated to a slick Torque converter box. The new alcazar also comes with a Torque converter with the 2L petrol engine. Torque converter boxes typically are lesser economical in fuel consumption, possibly why some manufacturers would hesitate to pair them with Petrols.
	(1) Thanks

11th July 2021, 23:23	#3
BeantownThinker BHPian Join Date: Nov 2011 Location: Bangalore Posts: 285 Thanked: 477 Times	Re: Torque Converter automatic for petrol engines I drive a Korean Petrol Automatic with a TC transmission. So you see these "mythical" creatures do exist. In the current market, I think, the Maruti Ciaz continues to offer a petrol automatic with a 4-speed TC AT. Before the advent of AMT/IMT/DCT/DSG, etc most of the petrol automatics had been TC transmissions. Hondas have conventionally been CVTs from as far back as I can remember. Hyundais of the past have also relied on TC transmission. It is only off-late that they have moved to DCT and IVT for their petrol engines. Now to the question as to why they have moved. The answer is simple. TC gearboxes are the most reliable BUT the most thirsty of gearboxes amongst all the auto transmissions. I drive a Verna petrol TC AT and get about 7.0 to 7.5 kmpl in the city and about 11.0kmpl on the highway fully loaded. From my experience when it comes to fuel efficiency it goes likes this for petrol engines Manual > CVT/IVT > IMT/AMT > DCT/DSG > TC. This is the reason why many TC gearboxes on petrol engines have been replaced with CVT or DCT. i10 has moved from TC to AMT and the i20/Verna/Creta have also moved from TC to IVT/DCT/IMT
	(4) Thanks

11th July 2021, 23:39	#4
TrackDay Senior - BHPian Join Date: Oct 2020 Location: Magic land Posts: 1,057 Thanked: 4,432 Times	Re: Torque Converter automatic for petrol engines I guess the Dual clutch gearboxes are provided for those who would like a more sporty performance with faster gearchanges. However I agree there have been issues with them, though some owners have managed to go on without any problems. The torque convertor is the oldest automatic going by general implementation if I am not wrong. The evolution has seen manufacturers go to other gearboxes and finally completing a full circle, returning to the trusty torque convertor. One point that is raised about them is the mileage and I guess this is why the Ciaz & Brezza have some mild hybrid in their automatics. How much mileage do the EcoSport, Rapid automatic (TC) owners manage to get from their cars ?
	(1) Thanks