997 fuel consumption

[w1how]

Averaged 25.4 mpg on the 440 mile round trip from my home to the Porsche festival on Sunday.Time taken for the journey was 5 hours 5 minutes so I wasnt exactly hanging around either.My car has the tiptronic gearbox,roof was down for most of the journey home(more drag),air con was switched off for the entire journey.

[911fan]

What is your opinion of that Redex fuel system cleaner fluid, is it worth using, does it improve mpg, or should not go near it?