How many miles do you get out of you A4 1.9TDi??

My 2.0 petrol is doing 25 mpg, nearly 27 if driven like a grandad. I suspect something is not right with mine.
 
130 tdi avant.
Last 5 months I've averaged 41 mpg and that's since air, oil, fuel filter change.
Egr and manifold clean out.
Tyre pressures always a little above recommended psi and thermostat is in full working order.
I think my 18" reps are my downfall.
41 mpg for a 1.9tdi fwd seems pretty poor.
 
Ah right, I'd heard others say about 18s reducing economy but didn't think about the weight. I think mine are normal Audi 9 spokes.