I don't understand how anyone
can't get over 40mpg out of a 1.4 when not hooning around, perhaps they don't realize there are more gears in the box

or of course that the throttle pedal has travel its not digital

Maybe you just have a lot of traffic?
for my Punto, 40+ when I want it

, averaging about 36 driven normally

, single digit on track
The lighter 500 should do similar/better.