Quote Originally Posted by Hadders View Post
Comrades,

Bear with me if these are naïve questions but I’m no mechanic.

From a mosey through the specs, I see that the 118’s 7 speed DSG gives better consumption than the manual. However with the 103 there is the usual situation where the manual is slightly better than its DSG, which is only 6 speed.

Why only a 6 speed for that diesel? Is it because with the extra torque 6 gears are enough and the 6 speed is simpler, cheaper and more reliable?

Do the consumption specs indicate that the 7 speed is a more efficient unit than the 6 speed. If so why not put the 7 speed in the 103, like in the 77 diesel, where the auto box also has a consumption over the manual in town?

Thanks,

Hadders (Martin Hadley)
No problems, there's a few good questions there.

The 6 speed DSG is actually more expensive and complex, but hopefully just as reliable. As the first DSG design VW used, it has has two multi-plate wet-clutches. VW have rated it as being able to cope with up to 350NM of torque - but as many people know, it can cope with much much more (even VW use it for their race cars....).

The 7 speed DSG is a newer design which aims to simplify things and lower the manufacturing cost and the costs of maintenance etc. It uses a new dry-clutch design. I'm not exactly sure what the max torque VW have rated this for, but I believe they've set it to around 280NM. It can handle more than that, but it won't be taking 550NM any time soon like some people are running with the 6sp DSG.

So the reason that the 103TDI has the 6sp DSG is due to the torque spec of 320NM on that particular engine.

As for fuel consumption, I believe it's more a case of how well the gear ratios used in the 6sp DSG or 7sp DSG match up with the characteristics of the engine. There are several VW models using the 6sp DSG which has lower fuel conumption than their manual equiv - including the Golf GTI.

Hope that helps