Hummer has expanded the product line to include the midsize H3 SUV. An unusual 3.7L I-5 borrowed from the Chevy Colorado powers the H3. The smaller H3 has the best fuel economy in the Hummer lineup. Stabilitrak® stability control provides additional safety on the road. Transmission options include a 4-speed automatic or a 5-speed manual. For off-pavement excursions, the H3 has an electronic locking differential and a 2-speed transfer case. An Adventure package offers larger tires for enhanced capability off-road. Hummer claims that the H3 can ford 24 in deep water at 5 mph, and climb 16 in steps or rocks.