2.5tdi v6 tweaking timing

[ms1083]

Just wondering if its better to be slightly advanced or delayed timing when adjusting the timing for the injection pump on VAGCOM. Obviously it needs to be "within spec" but is there an optimal setting for economy/performance.
I don't know if I am imagining it but I moved it to slightly advanced yesterday and am sure its running a little better (it was previously slightly delayed).

2.5 TDI V6 2004 Allroad - BAU engine

 

[myth]

I believe the factory default is http://i48.tinypic.com/2luswu1.jpg (which is -2) but as the engines gain miles on the clock, it's better to set the timing more advanced, near the green line ( around 0)

At a friend of mine, just would run nice around the green line, so I advanced it even more, to about +2.