[7] In 1913, Willys acquired a license to build Charles Yale Knight's sleeve-valve engine, which it used in cars bearing the Willys–Knight nameplate.

In the mid-1920s, Willys also acquired the F. B. Stearns Company of Cleveland and assumed continued production of the Stearns-Knight luxury car, as well.

The bankers hired Walter P. Chrysler to sort out the mess and the first model to go was the Willys Six, deemed an engineering disaster.

[8][9] To raise cash needed to pay off debts, many of the Willys Corporation assets were put on the auction block.

It gained a semistreamlined body with a slanted windshield, headlamps integrally embedded into the fenders, and a one-piece, rounded hood transversely hinged at the rear.

[15][full citation needed] Willys–Overland was one of two bidders when the United States Army sought an automaker that could begin rapid production of a lightweight reconnaissance car based on a design by American Bantam.

It took Barney Roos two years to perfect his engine, by a whole complex of revisions that included closer tolerances, tougher alloys, aluminum pistons, and a flywheel reduced in weight from fifty-seven to thirty-one pounds.

[19] In total, 647,870 military Jeeps were manufactured by the end of World War II, 362,841 by Willys, 280,448 by Ford and 2,675 by American Bantam.

[20] The word "Jeep" was first used to describe US Army "midget cars" in a January 1941 newspaper article, mentioning "Bantam" as the manufacturer.

The Ford designation "GP" did not stand for "General Purpose",[23] supposedly the "G" signifying government contract vehicle and "P" indicating the 80-inch wheelbase reconnaissance car.

[27] After the war, Willys did not resume production of its passenger-car models, choosing instead to concentrate on Jeeps and Jeep-based vehicles.

The first postwar Willys product was the CJ-2A, an MB stripped of obviously military features, particularly the blackout lighting, and with the addition of a tailgate.

Willys initially struggled to find a market for the vehicle, first attempting to sell it primarily as an alternative to the farm tractor.

[29] The same year, production of the Kaiser car was moved from Willow Run, Michigan, to the Willys plant at Toledo, Ohio.

[32] Also, an abortive plan was made to create a company called Chrysler-Willys do Brasil SA to build the 1956 Plymouth Savoy and a Dodge truck there,[32] in the hope of taking advantage of Willys' "Brazilian-made" credentials.

Willys–Overland was one of the first companies to enter the Brazilian passenger automobile market, and their early entry originally paid off, with sales spiking in 1954 when Willys became the number-one selling car.

[35] Being distributed by the family of Getúlio Vargas' closest advisor Osvaldo Aranha also helped, and Willys–Overland reached a 52% share of Brazilian passenger car production in 1959.

However, unlike in the case of the Argentinian Kaiser operations, which were essentially developed around hand-me-downs, Willys built a very modern plant from the ground up in Brazil.

[39] Willys expanded into Brazil's impoverished northeast in the early 1960s, when they built an assembly plant for the Jeep in the state of Pernambuco.

Willys also designed and showed a larger sports car called the "Capeta" (Devil) in 1964, powered by the 2.6-litre six-cylinder Aero engine.

[41] In 1965, Willys–Overland do Brasil and Renault began collaborating on a new front-wheel drive car, called "Project M" and meant to replace the aging Dauphine.

Kaiser-Jeep was sold to American Motors Corporation (AMC) in 1970 when Kaiser Industries decided to leave the automobile business.

After the sale, AMC used engines it had developed for its other cars in Jeep models to improve performance and standardize production and servicing.

[47] Only 12,800 were sold in 1933, 13,234 in 1934, 10,644 in 1935 (including a new panel delivery), and 30,825 the company's final year, making it a puzzle why it became popular: it was neither cheap nor plentiful.

[48] After the company revived, the 1937–1942 coupés, sedans, and pickups were again popular with hot rodders and gasser teams, and again, comparatively low production leaves unexplained why they gained so much attention.

[48] Ollie Olsen's Wil-A-Meaner 1940 coupé (driven by Bob "Rapid" Dwyer) won the 1961 NHRA Nationals A/G title.