To give you an idea on the Jazz, leaving Wollongong, up Mt Ousley, Across Picton, down the Hume to Canberra, and return, takes one take of fuel and averages 6.3L per 100KM ringing its little tit off at around 110KM/H the whole way (Not letting it cruise up the hills and lose speed... Giving it the shuffle back and getting up it)
It takes me around 35 - 38 Litres for that trip.
Around town (I live in Wollongong CBD, so often drive on the cold fuel map for most of my trips) I see 7 - 7.5L per 100KM, and that's having a fair bit of fun in it (Revving out to 5500RPM each gear basically with a fair bit of throttle)
I HAVE had my old Jazz as low as 5.3L /100KM, but that was keeping it sitting on 80KM/H on the freeways etc.
When I lived in Shell Cove, I regularly saw 6.0L flat per 100KM because to and from work was all smack on 80KM/H.