The Hummer H2 is notorious for having poor fuel efficiency, and is often used as the poster child for gas guzzling SUVs. In city driving, some owners report as low as 8-10 mpg, while others are getting 13-14 mpg on the highway. This is a topic that often causes intense debate over environmental responsibility, American automotive excess, and the actual price of owning such a vehicle. Now let’s see what H2 owners and critics have to say about its thirst for fuel.