2005 Citroen Xsara Picasso excessive fuel consumption

You could get the codes read to see if anything stored,But be aware that new diesel engines often do not meet the claimed consumption figures due to the compliance with emission standards,does the vehicle have a particulate trap,If so it may req,regeneration this can be done at your dealer,or by hard driving on motorway.

depending on the miles its done i would first get the cambelt timing checked just it case its been fitted slightly out, also if you have high mileage it would be a good idea get the injectors looked at for spray pattern, leaks, etc

Thanks to bustedknuckles and rizzo for the suggestions. The 2.0 hdi doesn`t have a particulate filter and I have given it a fairly good flogging but it didn`t seem to make any difference. The car has done 53000 miles so I would recon it`s still on its original cam belt but I will check it out along with the codes.As for the injectors, the car doesn`t smoke and seems to run OK but I don`t think it goes as well as my old one. It seems to have more bottom end power but drops off at the top end.