According to Motorcycle USA, the 2013 Harley Davidson Sportster Iron 883 has a maximum horsepower of 45.17 at 5900 RPM. Both the 883 Iron and 883 Low models of the Harley Davidson Sportster series are equipped with the same air-cooled Evolution V-twin engine at a displacement of 883 cc.
The Evolution 883 engine is rubber-mounted and coupled with a five-speed transmission. According to Motorcycle USA, the Iron 883 makes most of its power between 3200 and 4200 RPM and delivers a maximum torque of 53.8 pounds per feet at 3750 RPM. TopSpeed notes that the Evolution engine design is inspired by the classic Harley Davison Shovelhead and Ironhead engines.