Compare my fuelly:
GAS MIZR (Honda Insight) | Fuelly
to Eli's Insight #1:
Insight #1 (Honda Insight) | Fuelly
We've driven about the same distance (give or take 1000mi) at about the same average economy (he's got MIMA, but I have a much longer commute so winter doesn't destroy my economy quite as bad as it does his).
Over that distance, my fuel cost 144% of what Eli's cost.
The only major difference between us, is that he's in Santa Fe, NM, and I'm in Oshawa, ON.
Then remember that Europeans are paying about that premium again over Canadian prices, if not more.