Nissan X-Trail: Incorrect fuel consumption figures

I have read with interest the complaints of poor fuel consumption of Nissan X-Trails as mine is the same. When I communicated with Nissan I was told that they were not responsible for the figures posted on the windscreen as they were the results of a Federal Gov't agency and were the results of testing in a standard environment and were only provided so people could compare similar vehicles tested under the same conditions. I was told that the tyre pressures and the skills of the driver affected fuel consumption. Taking that on board I have travelled frequently from Maryborough to Brisbane Airport and return, 500 km or so with no traffic lights, no hold ups, light on the accelerator, the recommended tyre pressures and the best result I got was 10.9 L/100 km. I have had the car checked and there appears nothing wrong with it. Other owners with the 2.5-litre CRD I have spoken to have tried chips and exhaust mods but still cannot achieve the advertised consumption figure and they also continue to be fobbed off by both the dealer and Nissan. I am happy with all other aspects of the vehicle and I bought it to tow my caravan with planned trips of around 40,000 km, which it will do, but at approx 3 L/100 km more than the advertised figure I will use 1200 litres more than I bargained on. What really concerns me is do we have a gov't regulator providing incorrect consumer advice, so much for consumer protection, or are the manufacturers providing specifically tuned vehicles for testing. As always the motorist loses out.