Here is the reason I got my TDI with 6 speed manual and with that I suggest that you drive a DSG like the manual. Therefore, leave it in the "manual" position.
With that, the technique is to drive it at the lowest RPM's without lugging the engine...lugging the engine is very difficult to do in the first place with this trany/engine. I typically shift from 1st to 2nd at about 5mph and I am in 4th by the time I am at 30mph and 5th by 40mph. The engine does not lug. With that I squeeze out currently 49.6 mpg in my last tank of fuel.
With that, the technique is to drive it at the lowest RPM's without lugging the engine...lugging the engine is very difficult to do in the first place with this trany/engine. I typically shift from 1st to 2nd at about 5mph and I am in 4th by the time I am at 30mph and 5th by 40mph. The engine does not lug. With that I squeeze out currently 49.6 mpg in my last tank of fuel.