I searched that entire Spark/Beat Diesel thread with their search function for "kmpl", still searching the results but so far I found one results that is 18 to 22 kilometers per liter (~42.33-51.7MPG, US gallons) (
http://www.team-bhp.com/forum/offici...ml#post2923909).
Looks like the Chevy Beat isn't on Fuelly.
(
http://www.team-bhp.com/forum/offici...ml#post3009640) looks like about 33MPG, US gallons in rush hour traffic?
With the 2012 Prius C starting to pop up used in the coming years it would be smarter to buy one of those for the same price that you'd buy a new Spark. Traction Battery pack is small so not that costly to replace every ~15 years, more HP than Spark, automatic with ~52MPG real world average, US gallons. No brainer if you are into these micro cars. Or get a 3rd gen (2010+) regular Prius with 134HP, automatic and ~48MPG which right now is about $18K on cargurus. Of course the 2nd gen Prius is an option too
But a lot of people just buy new cars so then never mind
and (like what 'sendler' said) when you compare a used Spark with a used Prius the results change.