GM's Atlas inline-5: the quirky engine that powered the Colorado and Hummer H3

General Motors developed the Atlas inline-5 engine as an ambitious attempt to modernise its truck and SUV lineup, fitting it into models such as the Chevrolet Colorado and Hummer H3. The engine was mechanically complex and plagued by problems, making it a short-lived experiment. It stands today as one of GM's more unusual engineering detours.