High gas consumption
 

Hi,
I just bought 2011 x5 5.0i.
Before i owned 2004 X5 4.4 and had gas consumption in city about 17litre per 100km.
On new X5 consumption is more then 20l/100km. I already replaced air filters.
What else have to check to reduce consumption. By the spec e70 5.0 consumes less gas then e50 4.4
Thanks