Why is my Ford Galaxy experiencing poor fuel efficiency?

I recently bought a Ford Galaxy and it seems to be burning through fuel much faster than expected. I have tried adjusting my driving habits but it doesn't seem to make a difference. What could be causing this and how can I improve my fuel efficiency?

Low tire pressure can greatly affect fuel efficiency. Check your tires and make sure they are properly inflated.

You might want to have your car's oxygen sensor checked. A faulty sensor can cause the engine to burn more fuel than necessary.