Originally Posted by powers1

An Ecu remap for economy will also give much better performance.The torque limiters/revs are adjusted so that you get more torque at lower revs,letting the engine work better at these revs.Lower revs ,,better mpg.

However,if you are getting 23 mpg,something is wrong!You should be getting 30-35 mpg with or without a remap.
23 mpg is worst than a 3.0i and getting near 4.4 levels...

Before doing a remap,make sure your car is running nicely as standard.