Don't know who fed him that number, but it's a tad optimistic.
That would make it far, far more efficient than the one you guys are getting down under.
Tim has been looking at the Mirage's official fuel economy numbers in markets where it's already on sale (including Australia), then comparing them to other cars' ratings which we also have on sale in Canada/U.S. (e.g. Smart Fortwo, Toyota/Scion iQ, Chevy/Holden Spark).
From that, it looks like the M irage will have an EPA combined rating around 37-38ish MPG (US) - which very possibly makes it the best or 2nd best non-hybrid here. In Australia, looks like the only non-hybrid that beats it is the Smart Fortwo (only when the Smart is equipped with start/stop).
We've got details posted in a thread on the new forum. Working on the new forum now... Still hoping to have it open this weekend or Monday at the latest.