1.9 tdi 130bhp fwd vs quattro mpg

I have a 1.9 130 quattro and average 480 to 520 miles on a tank roughly 39mpg when calculated
 
as James says, quattro on the same engine usually costs around 3-5mpg, but 2.5TDI's aren't the same engine, so the difference can be a bit more than with the 1.9TDI's.

1.9TDI's in the 130bhp guise should be the best comparison...

6 speed TDI 130 FWD (48mpg) vs TDI 130 Quattro (6sp) (43mpg)

My 2.5TDI Quattro averages about 35-36mpg with a bipolar mix of 6th gear 50mph idling and ragging the nuts off it (diesel style though!)... if I'm driving it REALLY hard, then I can get the mpg down into the high 20's, but then my concern about the cost of what I'm burning is more about the rubber than the fuel!! We're talking traction control off and practicing trying to hold that balance while drifiting corners on "greasy" roads... which is fairly difficult with a big torquey TDI lump and that turbo... it's either hooked up completely or going into lairy oversteer, but not much in the middle... not like my old E30 Bimmer (from a few years ago!).

Even a 2 mile heavy traffic slog to the shops will usually see my avg mpg creep up into the 30's by the time I get there, high 20's if it's an especially bad tempered stop/start bumper-to-bumper slog....

I've measured actual vs DIS a few times and there's a few percent difference, not much at all really...
 
Talking of the DIS, anyone know how to change the sampling range that it uses to calculate the range? Handbook says it is measured over last 50 miles, but mine changes so quickly when you accelerate its more like over the last 10 miles.
 
Are you looking at the #1 or #2 average?

#1 average is just the current trip or the last X miles (50 sounds about right), but it will only take whichever is the shortest.

I'm pretty sure that the #2 average is based on the average since #2 trip computer was last reset, I tend to reset mine every tank.

Speaking of which, recent average seems to be down to 33.x mpg, I had been stuck in some pretty ugly traffic jams, but have subsequently had a good long motorway blast and average only crept up to about 35mpg, which is a little strange since that was mostly 100% legal-speed and certainly no silly business... so would have expected high 30's really.... have Audi sabotaged my car?!?
 
What are the differences.
Owners here worst and best mpg/ miles per tank etc?

I generally get about 550 / 46mpg to a tank which is just daily commutes which is a mixture start/stop (traffic in to Nottingham!) and dual carriageway. This was always with V-Power Derv, however at the last fill up I decided to put 'Fuelsave' in and I am currently getting 48mpg, 420 done and DIS showing 245 left in the tank! Surely this must be down to a lighter right foot and not the fuel? Sorry to Hijack the thread but has anyone else tried this fuelsave stuff?