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[Audi A3/S3] Why does DSG gearbox give better fuel economy?


Guest slittley
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Guest slittley

These are the figures quoted by Audi for two A3s

(1) A3 Sportback 2.0 T FSI Sport Manual

According to 1999/100/EU in mpg

urban 22.6

extra urban 40.4

combined 31.4

Unladen weight 1470kg

(2) A3 Sportback 2.0 T FSI Sport DSG

According to 1999/100/EU in mpg

urban 26.2

extra urban 45.6

combined 35.8

Unladen weight 1410kg

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Notice that the car with DSG has a significantly better fuel economy than the one with the manual gearbox. The DSG-equipped car is 4% lighter (60kg) than the manual-version but this alone does not explain the 14% improvement in combined fuel economy.

I can understand the DSG car having improved acceleration through faster gearchanges but am left wondering why the economy is so much better.

Any ideas/comments?

Cheers

Steve

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My guess would be that it's because with DSG the turbo is always on the boil where as with the MT you have to boost it back up again everytime you change gears. I would say you can also get the same acceleration with less throttle for the same reason.

Unfortunately the MT is not available over here so I haven't been able to compare the two...

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Hmm, surely if the turbo is puffing more then it will be burning ALOT more fuel? Certainly the case on my S3!

I imagine its more to do with the fact that the test was run in "auto" mode and that the DSG was changing up a lot earlier than most drivers would in a conventional manual?

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I'm guessing though that with a manual you would be getting overboost every shift change, if you push that hard.

Mine spends most of it's time at various levels of vacume and only really boosts if you really put your foot down. Then it might shoot up over 100kPa but then settles around 50kPa. Then as it shifts it might dip 10 or 20kPa.

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The DSG is simply much more efficient than a manual gear box, the days of auto-boxes being fuel hungry have gone now.

The DSG is a six speeder, it will always select the right gear and shift ratios without loss of drive. DSG is seriously neat - but don't get conned into thinking it is a manual with an auto-box added on as many seem to have done.

DSG is a clever auto-box, the paddles and S mode just make it more fun.

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DSG is more economical as others have said because it can choose a better gear for better economy. At 30 mph or a little above it it can be in 5th gear where most would leave it in 4th in a manual. This isn't a problem as a prod on the throttle will have it in 3rd or 2nd faster than you could in a manual by a mile.

Plus when you do things like give 50-60% power from the lights instead of the revs going fairly high in each gear in a manual. DSG shifts up and surfs the torque curve meaning its far more economical than the manual as they are on the whole getting driven in a different way.

All in all it puts you in the best gear all the time and if you want more performance just press harder, simple. S can be used but if you are on anything other than maximum attack it really isn't needed and I prefer to put it into manual then anyway and play with the paddles.

DSG isn't a manual with acutators like some systems are in Alfas - Ferrari etc. its much more clever than that and a completely different design. I won't bore you all with the details but it works and is easily as god as a normal auto in 95% of situations and has none of the fuel draw backs. 169144-ok.gif

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Guest slittley

Thanks everyone for the answers. I am planning on ordering a 2.0T model within the next few weeks and wasn't sure if it was worth paying the extra £1400 pounds for the DSG version. I think I probably will go for DSG.

I'd like to order in December but I have heard that better discounts may be available in January when trade is quieter. I don't know if this is true or not.

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[ QUOTE ]

Thanks everyone for the answers. I am planning on ordering a 2.0T model within the next few weeks and wasn't sure if it was worth paying the extra £1400 pounds for the DSG version. I think I probably will go for DSG.

I'd like to order in December but I have heard that better discounts may be available in January when trade is quieter. I don't know if this is true or not.

[/ QUOTE ]

hehe by the sounds of it your unhappy with your soot chucker and need more omph! the 2.0T FSI is a fine engine.

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[ QUOTE ]

I'd like to order in December but I have heard that better discounts may be available in January when trade is quieter. I don't know if this is true or not.

[/ QUOTE ]

I don't know about the timing in the UK but I was told by the director of a dealer group here that the month before closing the books and long holidays are good times to buy.

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