Golf GTD: DSG fuel consumption higher: Why?

[Andy B]

I currently drive an Edition 30 DSG, and I remember when I bought it that the official DSG fuel economy figures were better than the manual, which I'd expect, given that the gear changes are very quick and the box moves quickly to a high gear in relaxed driving to save fuel.

I've been wondering about the GTD since it seems to be not that slow and much more economical, but whereas the manual is listed at 67.3mpg, the DSG option is listed at just 60.1mpg. (Still very good, and only £30 per year for road tax too, but 7mpg is 7mpg!).

Why is this?

I know that the official figures bear little resemblance to the real life mpg figures, so it may just be that the DSG doesn't seem so economic when put through the rolling road European Driving Cycle test from which the mpg figures are mystically generated, and that in the real world it won't really be that much less efficient.

Or is it that the DSG gearboxes are today filled with porridge?

Or what else?

I know some people hate DSG, but having done 65k with one, I don't think I can go back to a manual. The last time we came back along the M4 there was a big hold up because of roadworks, and the thought of pushing a car up a slow incline at 3mph for 30 minutes on the clutch makes my left leg start twitching. And I quite like burning up faster cars driven by people who can't change gear properly 

I suppose we could just wait till the real world figures come in...

[Jimble]

No idea but the mk6 GTD with DSG fitted is worse than the manual by about 4~5 mpg whereas the ed35 is about 1~2 mpg better with DSG, go figure?!

[SoundillusioN]

I mentioned this in another thread.  The GTD is apparently more economical than the 150ps I've ordered, go figure. 

[Sootchucker]

The 6 speed wet clutch boxes are of a completely different design to the 7 speed dry boxes.

The 6 speed is oil bathed and is able to take a much higher torque loading than the 7 speed models, which use dry clutches. I think it's the different construction of both that makes the difference. You tend to notice that smaller petrol engines with the 7 speed box are more efficient, whereas the more powerful cars with the 6 speed less so.

[Snoopy]

In general due to weight and gearing the dsg models in the past are often slightly more thirsty in real life.

[Andy B]

You tend to notice that smaller petrol engines with the 7 speed box are more efficient, whereas the more powerful cars with the 6 speed less so.

Which is odd then, because my edition 30 (mk5 golf) has a 6 speed DSG, and it is rated as more economical than the manual version... hence my confusion about it no longer being the case.

Maybe today's 6 speed DSG is a different design from the old one. Maybe it handles more power at the expense of efficiency. Maybe it has been redesigned to be cheaper to build at the expense of efficiency. Who knows!

[Poached]

A Seventh Gear will play quite a role in cruising economy over the 6 speed box...

The RS3 has a Seven speed DSG so there is a Seven speed box available to handle the torque.