Stewart and Stevenson
Stewart and Stevenson is a manufacturer of military vehicles and equipment related to the oil industry. The military vehicle division became a part of BAE Systems in 2007, while the oil equipment division was acquired by Hushang Ansary in 2006 and operates as Stewart & Stevenson LLC.
For a brief stint in the 1980s and 1990s, S&S manufactured transit buses. The most notable model was the Stewart and Stevenson Apollo T-40, a number of which are still in service for the LADOT in Los Angeles, California. S&S also produced the Villager midibus as well as the Starship S-28 and the Gemini T-30, none of which are in current operation.
In 2006, S&S partnered with New Flyer Industries to create the NFI/S&S DE40i hybrid "Invero" transit bus. While the majority of the bus was built by NFI, S&S was responsible for installing the GM/Allison hybrid system. The only DE40is in existence are the four operating for the Roaring Fork Transportation Authority in Aspen, Colorado.