I have a 52 reg 1.9TDI 130BHP, all standard apart from 18" BBS LMs and lowered on coilovers. I only use shell diesel.
Have owned the car for 7 years and have noticed the fuel consumption to be very poor. Only use it around town and only manage to get 380miles from a tank 400 at a push.
I always change gear around 2K revs and never push it hard. I took it on a long distance trip last weekend and managed 450 miles out of a tank at speeds of around 60-80mph.
I have done a full service 3 months ago including the fuel filter. I have also put Forte diesel treatment in but the mpg has remained the same.
This year i have replaced the thermostat, water pump, cambelt and temperature sensor and also cleaned the intercooler, EGR and done the mr muscle manifold clean. I also checked the pipes for any leaks/cracks and looked the the turbo actuator and seemed ok.
I have put it on vagcom and there are no errors at all.
See below graph of Block 11 log from 2000-4000rpm in 3rd gear