I know most long time hummer drivers think I'm crazy when I say you can do 17mpg in an H2 but it is possible I did it over two tanks but your basically hypermilling the hummer. It takes doing things like throwing it into neutral downhill slow starts to the point of speeding letting it drop down to 10-20mpg below the speed limit then slowly bringing the speed back up again. Drafting as much as possible. I got obsessed when I saw someone else getting way better gas millage than me on this forum and set off to figure out how to change my driving style to get higher mpg. When I got mine the last year the DIC read 9.8. I'm now at 12.3 and I'm running 14.5mpg on this tank. Also the only mod I've wone was possibly over inflating my tires at 40psi. I questioned in the forum and 85_305 re-affirmed my fear that popping it in and out of nuetral wasn't a good idea, so I started backing off the crazy push it to the limit driving and now I'm almost always north of 14 unless I spend a lot of time in traffic, sit in a drive through for a long time, or peddle it down just to hear the engine roar like a vet pulling an 18 wheeler.

 

Its really not that impossible... stock maybe though. I get about 12.8 miles to the gal. going to work.. averaging about 50 miles per hour. Have the usual hills and stuff. Freeway driving best I did was 15.2 with no AC on and that was going from TX to AL. Its all on the way you drive it. I service it regularly and keep the tire presure up at 50 psi. I will lower the tire presure when I take it off road. Have a 107K on her.

 

I never got anywhere close to 17 mpg. Didn't try as hrd as you guys though.