Which gives better fuel consumption in an auto gear?

badaveil

Wrench Pro
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13
From
Malaysia, Kuala Lumpur
Car
Peugeot 407
Often one makes comparison in fuel consumption between a manual and automatic gearbox but here, I wish to know in cars with automatic gearbox that can shift between automatic and manual setting, which delivers better fuel consumption assuming both are driven in the same driving style? :confused:
 
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HDi fun

TC ModFather
Points
637
From
Buckinghamshire UK
Car
Passat 2.0 TDi
Do you mean automatic cars with torque converters compared to manual cars with mechanical clutches. If so then the manual car will generally give slightly better economy.

But you did mention automatic car driven with the driver selecting gears manually. And in that case there will be no difference to speak of.

I answered the question you asked.
 

T9 man

TC ModFather
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I think I see what the OP is asking HDi - Badaveil - There would be no discernible difference between the fuel consumption on a standard automatic gearbox and an automatic gearbox with a manual shift selector. I have the fancy tiptronic version and although it is great to use on a track and occasionally on the motorway, for everyday use you use the full automatic facility of the gearbox. If you use the autobox in manual mode then you do run the risk of using more fuel simply because YOU are selecting when to shift change up and down through the gears, therefore you will be shifting outside the programmed criteria of the autobox controller or TCS.
 

badaveil

Wrench Pro
Points
13
From
Malaysia, Kuala Lumpur
Car
Peugeot 407
I have the fancy tiptronic version and although it is great to use on a track and occasionally on the motorway, for everyday use you use the full automatic facility of the gearbox. If you use the autobox in manual mode then you do run the risk of using more fuel simply because YOU are selecting when to shift change up and down through the gears, therefore you will be shifting outside the programmed criteria of the autobox controller or TCS.
Yes, yes. I mean the auto gearbox with the so-called "tiptronic" thing. So when you mean 'autobox in manual mode', you meant in "triptronic" mode? :embarrest:
 

HDi fun

TC ModFather
Points
637
From
Buckinghamshire UK
Car
Passat 2.0 TDi
I have a Tiptronic 6 speed unit too. BMW calls it Steptronic - it has all sorts of clever sub modes (BMW calls this Adaptive Automatic Transmission) left to itself like inhibiting changes when the car is taking tight bends and not changing up on long hill descents but it's the same thing.

But surely if I am driving in the same style then I'd be changing up and down at roughly the same points as the ECU would choose anyway. Which constitutes the same driving style! So economy would be nearly enough identical!
 

badaveil

Wrench Pro
Points
13
From
Malaysia, Kuala Lumpur
Car
Peugeot 407
But surely if I am driving in the same style then I'd be changing up and down at roughly the same points as the ECU would choose anyway. Which constitutes the same driving style! So economy would be nearly enough identical!
Yes, I see and agree with your point. So does that mean the triptronic mode should not be used if a driver has fuel economy in mind? :blink:
 

HDi fun

TC ModFather
Points
637
From
Buckinghamshire UK
Car
Passat 2.0 TDi
Not really, it's only there if you want to take control of the gear changes yourself.

After a few weeks with an adaptive transmission it learns your driving style to a degree and also you, as the driver, learn how to influence its behaviour by adjusting accelerator pedal pressure slightly.

I use the Tip/Step mode occasionally but in general I find normal automatic gives enough response for my needs. It does adapt in lots of ways. If you push the accelerator down rapidly it will instantly engage one from a number of performance oriented gear change patterns. This is different to normal kickdown operation.

You can also manually select a Sport program which tightens up the torque converter and holds lower gears for longer. The shifts also tend to be slightly 'firmer' in sport program whereas in normal the shifts are virtually impossible to feel at all.

A good automatic transmission can be a joy to drive in all kinds of situations. A bad one can be very very annoying and even dangerous.
 

badaveil

Wrench Pro
Points
13
From
Malaysia, Kuala Lumpur
Car
Peugeot 407
Not really, it's only there if you want to take control of the gear changes yourself.

After a few weeks with an adaptive transmission it learns your driving style to a degree and also you, as the driver, learn how to influence its behaviour by adjusting accelerator pedal pressure slightly.

I use the Tip/Step mode occasionally but in general I find normal automatic gives enough response for my needs. It does adapt in lots of ways. If you push the accelerator down rapidly it will instantly engage one from a number of performance oriented gear change patterns. This is different to normal kickdown operation.

You can also manually select a Sport program which tightens up the torque converter and holds lower gears for longer. The shifts also tend to be slightly 'firmer' in sport program whereas in normal the shifts are virtually impossible to feel at all.

A good automatic transmission can be a joy to drive in all kinds of situations. A bad one can be very very annoying and even dangerous.
A very good and interesting reply. I will keep them in mind. Thank you very much
 

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