Kenworth Truck Company is an American truck manufacturer. Established in 1923 as the successor to Gersix Motor Company, Kenworth specializes in the manufacture of heavy-duty (Class 8) and medium-duty (Class 5-7) commercial vehicles. Headquartered in the Seattle suburb of Kirkland, Washington, Kenworth has been a wholly owned subsidiary of PACCAR since 1945 [1] and has operated with sister company (and market competitor) Peterbilt Motors.

Kenworth has achieved many firsts in truck production; Alongside the first truck built with a standard diesel fueled engine, the company introduced its first heavy-duty truck with a raised roof sleeper cab and an aerodynamically optimized body design. The Kenworth W900 has been produced continuously since 1961, serving as one of the longest production runs of any truck in automotive history.

Kenworth's roots date back to the founding of Gerlinger Motors in Portland, Oregon in 1912; The company was a car and truck dealership owned by brothers George T. Gerlinger and Louis Gerlinger, Jr. [3] In 1914 the brothers expanded into vehicle manufacturing, marketing a truck called the Gersix. [3] Named after its in-line six-cylinder engine (one of the first trucks of its kind to be equipped with [3]), the Gersix is ​​made of structural steel designed for commercial use.

Although the first vehicle was largely completed as a side project, the heavy-duty construction of the Gersix was in demand by lumberjacks in the Northwest. [3] [4] In 1916, Gerlinger Motors moved from Portland to Tacoma, Washington, renting a building from Seattle businessman Edgar K. Worthington.

In 1917, Gerlinger Motors filed for bankruptcy and was put up for sale when EK Worthington bought the company with business partner Captain Frederick Kent. [4] [5] The company was renamed Gersix Motor Company to highlight its connection to truck manufacturing. [4] In 1919, Captain Kent retired with his son, Harry Kent, replacing him as company partner.

In 1922, Gersix produced 53 trucks in its final year at its factory on Fairview Avenue in Valley Street. [5] Following continued strong demand for the model line, the company found itself with $60,000 to reassemble and relocate its headquarters.