Hi Jocko
Glad you finally made it onto the forum!
The Jazz is a great car, we have a 2010 Jazz Si (1.2 also) which in my wife's hands (normal driving

) does mid 40's. When I drive it and hypermile, it can easily do 60+ and on a longer run (drafting lorries etc., max speed 60mph) I've seen 70+.
The 'magic seats' are brilliant, I've fitted a mountain bike in there and other large objects!
If you feel like posting your mpg adventures please feel free to add them to our MPG stats threads. Latest one is here
viewtopic.php?f=17&t=1233&start=30
I will own up to some engine off time but only in the Jazz and generally low speed short trips when no traffic about - it has resulted in many 100+mpg runs

'15 Audi A3 Sportback SE CoD S-Tronic - 5+ year average 55+mpg
(Retired) '06 Honda FR-V 2.2 i-CTDi - Best/longest tank: 67.92mpg (+51.6%) / 815.5 miles.