I average 12.1 @ 38K miles. Mix of highway and lots of traffic jams with the A/C blasting. The mileage isn't that bad for a truck anyway, even the Honda Ridgeline all wheel drive truck only gets 17 mpg with a V6. The H2 is made to run on regular gas and lots of it with that 32 gallon tank. It only hurts when the price jumps up. The most I have ever put in it was $65!
If it don't go chrome it!
http://home.comcast.net/~mbdougl2/2003h2.htm