Automatics with torque converter lock-up?

[sgiitk 0]

After trying for a long time aqnd not getting a satisfactory respose I am now putting this question straight out.

Which, if any, automatic transmissions on Indian Cars have a torque converter / clutch lock up? For the uninitiated, at speeds higher than a minimum the transmission locks out (i.e there is a rigid coupling of the input and output shafts) the torque converter, and hence the fluid loss inherent in the Torque Converter. This reduces the power losses and improves the economy.

As far as I know the Skoda/VW DSG box may be the only one meeting this requirement. Which are the others? Will the Guru's please enlighten us.

[rohit 0]

here's the bit of information i found related to your topic

 

Although the torque converter clutch is not part of the engine, it can make the car feel like the engine has a problem. The torque converter clutch is also known as a lock up converter. The lockup clutch has many purposes and is part of the transmission. A regular converter in an automatic transmission is made to slip at idle so that the car doesn

[roadangel 0]

The new Honda City will also come with one.

[sgiitk 0]

now to your query which indian cars have a torque converter/clutch lock up?

mercedez benz ml-320

skoda laura

volksvagen tiguan

hyundai santro automatic to name a few

 

Merc. I would expect it. That is a plus point. The Beemer may also have it.

Laura  & Volkswagen Tiguan- I already mentioned the DSG box

Santro: I doubt it. I own one and does not seem to behave like it. Also, fuel economy of 10kpl makes s TCC questionable. Could be that only the 4th gear (labelled as OD, since the box is essentially a 3-speed with the fourth added on) has this. It does not switch to fourth much before 45-60kph!

[Charlesp 0]

Honda Civic

[rssh 59]

No H Civic doesn't have this

[rohit 0]

now to your query which indian cars have a torque converter/clutch lock up?

mercedez benz ml-320

skoda laura

volksvagen tiguan

hyundai santro automatic to name a few

 

Merc. I would expect it. That is a plus point. The Beemer may also have it.
Laura  & Volkswagen Tiguan- I already mentioned the DSG box
Santro: I doubt it. I own one and does not seem to behave like it. Also' date=' fuel economy of 10kpl makes s TCC questionable. Could be that only the 4th gear (labelled as OD, since the box is essentially a 3-speed with the fourth added on) has this. It does not switch to fourth much before 45-60kph!
[/quote']

you can refer to following link for details regarding santro

http://www.santroxing.com/santromain2.asp?pagename=com

also i am pasting the same for your reference

-Speed automatic transmission

Now enjoy the freedom from stick gear shifting & frequent clutch pedalling with the Santro Automatic.With an electronically controlled 'intelligent' power train system, the Santro Automatic offers the most relaxed way to counter busy city motoring. The 4-speed transmission features a compact ultra-light weight gear train, high performance torque converter and hydraulic-electronic control, offering four forward gear ratios to deliver a wide array of speeds for varying city traffic conditions.

the reason for low mileage is already stated in the article pasted earlier.

[rohit 0]

@ rssh - for your reference

Civic: 5-Speed Automatic Transmission

The Civic Sedan and Civic Coupe are available with an electronically controlled 5-speed automatic transmission. The 5-speed automatic transmission - a first for the Civic - is all new for 2006 and improves on the previous 4-speed automatic design with a wider overall ratio that maximizes acceleration in gears one through four and optimizes fuel economy in its overdrive fifth gear. The computer controlled direct control transmission provides amazingly smooth shifts.

The direct control coupled with gear ratios that are closely matched to the output of the engine help extract more power from the engine at just the right time to provide overall vehicle performance competitive to vehicles with 4-speed automatic transmissions and more horsepower.

The 5-speed automatic transmission uses a wide variety of technology that provides smoother shifting as well as reduced friction for enhanced efficiency. Those technologies include a low-friction clutch and a special super-thin torque converter. The thin torque converter results in a compact transmission unit. Other space saving measures include a double-row idle gear and a tightly packaged second-gear clutch.

To improve powertrain smoothness and reduce gear "hunting" on steep grades, the 5-speed automatic transmission is also equipped with a standard Grade Logic Control system. Using sensors that monitor throttle position, vehicle speed, and acceleration/deceleration and then comparing these inputs with a map stored in the transmission computer, the system is able to determine when the vehicle is on an incline and adjust the shift schedule for improved climbing power or downhill engine braking.

To improve fuel economy while maintaining a high level of drivability, the 5-speed automatic transmission includes an active lockup torque converter. With the precise control afforded by a linear solenoid, the system expands the speed and throttle setting range in which lockup can be engaged.

[rssh 59]

Well I thought that only Skoda VW have them .Anyways this should improve the economy ,so why does civic and Santro A/T lack behind .

[sgiitk 0]

@rohit : Thanks. I do not think the Santro advt. even though very cleverly worded mentions TC lockup. The Civic is explicit.

Not surprising since the Santro box has far tighter cost constraints. Also, the tragedy of it all as that after the wagonR/Santro/i10 the next automatic is the City : Zilch in between.

[rohit 0]

your welcome Sir. yes wish there were some options for automatic between 4 lac and 8 lac bracket

[mehul_bhp 0]

well totally alien stuff for me as i have never driven an automatic !!! i would like someone to explain me the DSG-TWIN CLUTCH TECHNO ~~~

[rohit 0]

you can refer to

http://en.wikipedia.org/wiki/Direct-Shift_Gearbox

 

http://en.wikipedia.org/wiki/Twin-clutch_gearbox

[rssh 59]

Good information @ rohit also did Pete modified a DSG gearbox Laura or the manual one .The disadvantage are more in number for DSG ,like it can be disordered easily and no modification in car tuning will be passed on .

[sgiitk 0]

I guess he did the manual. On the automatic since the throttle will be pressed less the upshift will naturally happen at a lower speed. The pedal position is one of the parameters used to decide the shift. Try an automatic, just ease off on the throttle and if you are in the right band then an upshift happens almost immediately.

[Charlesp 0]

@Rohit: Thank you. Saved me some searching.