Diamond T (United States)

Diamond T Motorcar Company was established in 1907 in Chicago, Illinois, by C.A. Tilt, who was the son of a shoe manufacturer. The company adopted a distinctive trademark featuring a "T" inside a diamond, which contributed to its memorable branding. Tilt began experimenting with car designs in 1905, but the company did not officially enter the automotive market until 1907, when it introduced a large and expensive 40-horsepower car available in runabout, tourer, and limousine models, priced between $3,250 and $4,250.

In the following years, Diamond T produced models designated as 50 horsepower for 1908 and 1909, although these likely utilized the same engine as the earlier models. By 1910, the company offered a smaller 30-horsepower engine, and the limousine model was discontinued. The production numbers for the early years included fifty cars made in 1907, with total production likely reaching several hundred units.

In 1911, a significant shift occurred when one of Tilt's customers requested a truck. This led to the development of a truck using a car engine but featuring a chain drive instead of a shaft drive. The trucks gained considerable popularity, prompting Diamond T to discontinue its car production. The company became well-known in the American truck industry and continued operations until 1966, when it merged with REO, another former car manufacturer, to form Diamond-Reo.