10.4 km per litre (9.6 litres per 100 km - 30 mpg approx) seems high. Has it got worse since you have owned the car?
You could also check your brakes are fully releasing properly. They can sometimes stay partly stuck on due to dirt and corrosion in the moving parts.
One way of checking this is to drive the car for half a kilometer or so without using the footbrake at all, if possible, except to gently stop. The brake parts such as disc, drums should still feel fairly cold. If one or more of the brakes , front or rear , gets noticeably hotter than the others it may be binding. You may be able to tell it is very hot without touching it but if necessary wet your finger and very briefly touch the brake part. But be careful not to burn yourself. Brakes can get red hot.
Also this fuel consumption may be normal if you only do short journeys in heavy city traffic .
