Now a brand of Maxima Technologies, Stewart Warner is perhaps the most recognized name in vehicle instruments in the history of the U.S. automotive industry. In fact, the brand dates back to 1905 when John Stewart founded Stewart & Clark Company. Stewart brand speedometers were first used on original Ford Model Ts, after which the company established itself as a market leading supplier of instruments. Seven years later, in 1912, Stewart and Edgar Bassick joined forces to create a new company to manufacture vehicle instruments and horns. Bassick, whose acquisitions included the Alemite Company, and Stewart also acquired the Warner Instrument Company and, as such, the Stewart-Warner Instrument Corporation was born.

Started in Chicago, the firm erected a manufacturing plant on Diversey and over time, the operation expanded outwardly in all four directions, thus becoming a massive complex with over one-million square feet and six floors. Prominently situated in the middle of the factory, towards the front, was a huge clock tower featuring the words "Stewart" and Warner". Off to the right was another tower, also featuring the words Stewart Warner, that could be seen for miles around. Today, the old clock resides in front of an apartment complex on Diversey as the only reminder of this once sprawling facility.

Over the years, Stewart Warner supplied a majority of the instruments, hourmeters and senders used by not only the automotive industry, but also by the heavy-truck and off-highway markets. The firm also supplied a wide range of unusual products like radios and refrigerators. In its heyday, Stewart Warner was a powerful corporation that employed thousands of people.

In the 1980s, Stewart Warner was acquired by British Tire & Rubber (BTR) who later, in the early 1990s, made a decision to relocate the operation to Juarez, Mexico. Subsequent to this move, another management team acquired the assets of Stewart Warner from BTR and split off from sister companies Hobbs and Alemite. In early 1998 Datcon Instrument Company, acquired Stewart Warner and in March 1998, the entire enterprise (including Spanish acquisition Industrias Jorda, S.L.) was renamed Maxima Technologies. Maxima decided to retain former company names as brands (Stewart Warner, Datcon and AST) in order to sustain these brands in their core market segments.

Today, Maxima and its Stewart Warner brand are poised for even bigger and better things. Backed by a strong management team, the firm's future is buoyed by numerous recently-won O.E.M. contracts and a rededication to the Stewart Warner brand and its core aftermarket.