Tuning for economy

[Germs]

I have an '06 SL500 and I love it but it is not the most economical car in the world (for very good reasons I know). Nonethless if there is a way of improving mpg without sacrificing performance I would love to know. Looking at ads for remapping the ECU it seems they major on increased performance and mention almost as an aside increased mpg. Is there anybody out there who has taken this, or any other route, and liked the results? Let me stress again - I love the car and have no intentions of changing it, just trying to ease the budget that's all.