Maybe reset your average and see what it is now. I recently bought a 147 and the onboard stats had never been touched, so no matter how I drove, fast or slow, it would take a lot of mile sot make the average change by 1 mile.
Reset them and then you'll have a better idea of what you are actually doing. I tend to look at the actual consumption.
Also it really comes down to how fast you accelerate, what gear you drive in around town, and how fast are you going on the motorway? I find my 2.0l 147 revs higher at 80 than my 1.6 golf at the same speed.