Help needed

Lowering won't improve economy, trust me I know.

All it will do is make you want to press the loud pedal even more, to see if you can get around the twisty bits faster.

The figures you are achieving sound about right if you enjoy the foot to the floor type of driving, don't forget also its winter, blooming cold. I know these little engines get to operating temp very quickly but they still use more juice in winter, fact.