High Fuel Consumption (2011 2.0 TDI)

[robb969]

2011 (61 Plate), VW Scirocco GT 2.0 TDI (150PS), 144000miles

I did an oil, oil filter and air filter change a week ago along with replacing the front discs and pads.
Ever since, fuel consumption has been down by around 7mpg (usually 55-60, now 48-50).
Thought it was brakes bedding in, not the case, no wear from the brakes, not hot, no binding sounds.
No obstructions in air filter or ducting.
Oil used was VAG Shell Helix Ultra 5W-30.
All filters used are Bosch.
No engine warning light.
No fault codes.

Used OBDII and found that:

Speed (mph) ~~~ AFR ~~~ Fuel Flow (L/hr)
0/Idle ~~~ 3.62:1 ~~~ ~3.2
40 (5th) ~~~ 1.73:1 ~~~ ~8.8
60 (6th) ~~~ 1.79:1 ~~~ ~10.3

...these values, seem right. Shouldn't this be closer to 14.5:1 and <1L/hr at idle ??
Engine was up to temp after 20 mile motorway cruise.

Any ideas? Anything else to check before getting proper VAG-com plug in?

Many thanks in advance.
Rob