Holden claims the fuel consumption of the petrol Captiva is 16.4 L/ 100 km in urban, or city, driving conditions, but that drops to 8.9 L/100 km in extra urban, or country type driving. On average, the company claims, the Captiva would average 11.6 L/100 km. You say yours does 6.2 km/litre, which equates to 16.1 L/100 km, and that's in line with Holden's claims for urban driving. When you look at the labels on the windscreen you need to take in all of the information, not just the combined, or average, figures. The main thing they are there for is to allow you to compare one vehicle with another rather than give you an outright number that you will get from the vehicle yourself. Before complaining to the dealer I would do what has been suggested, that is to run it for the 15,000 km. You should see a reduced in the consumption as the vehicle beds in.