I'll say this again: A VR6 /R32 engine is a thirsty beast and you really need to bee at the top of your game on servicing etc Its a fickle beast that if not looked after will result in poor mileage.
When was the last time it was serviced, all the filters changed, plugs etc? they need to be spot on.
Next, any misfires? again needs investigation and sorted as this can result in poor mileage
O2 Sensors - the VR6 especially was prone to lunching the sensor - I went through 2 in a matter of months before getting it right.
Throttle body - the butterfly should be spotless i.e not covered in carbon, clean and lubricate using 3in1 oil.. when you hold up the body to the light, there should be the finest of light seen around the butterfly
Hope this helps.. I was always tinkering with my VR6 and was the only one on the forum at the time to get text book mileage and I'm no slouch either...
Here's the recommended figures for the van, so I'd say you're doing not to bad:
I had the 3.2 v6 audi tt 245bhp not much you can do in way of performance and fuel consumption except drive as smooth as possible. Which is pretty hard when you hear the noise that comes out of it when accelerating hard.