In 1899 Adams moved to London and joined the Sturtevant Engineering Company who manufactured fans and air handling equipment.
It was a "gas buggy" along the lines of an Oldsmobile and following agreement with Adams production of the car started in 1905 as the Adams-Hewitt.
The car had a supposedly foolproof two, later three, speed-epicyclic transmission with a 1724 cc 10 hp single-cylinder engine located horizontally in the middle of the chassis driving the rear wheels by chain.
[3] In 1910, the company produced an advanced 16 hp four-cylinder model with front-wheel brakes; it came with compressed-air starting, tire-inflating, and jacking equipment.
The "pedals-to-push" gear was still offered, as was a conventional four-speed transmission and an unusual planetary gearchange (three-speed), which was operated by a pedal that moved in a gate.
Adams also manufactured commercial vehicles, including taxicabs and three-quarter ton lorries; these were also based on Hewitt designs.