The Hummer H3 was a four-door mid-size SUV produced by Hummer from 2005 to 2010. Based on a modified GMT345 platform shared with General Motors' midsize pickups, the H3 featured three engine choices: a 3.5 liter gasoline-powered engine, a 3.7 liter gasoline-powered engine, and a 5.3 liter V8. It was the smallest of the Hummer models, and was positioned below the H2.