From 1902 until 1908, Jeffery moved steadily to bigger, more reliable models starting with the 1902 . Jeffery cars were built on assembly lines (the second manufacturer to adopt them—Ransom E. Olds was first), and in 1903 Jeffery sold 1,350 Ramblers. By 1905, Jeffery more than doubled this number. One reason may have been because Charles went back to the steering wheel before 1904. In 1907, Jeffery was building a large variety of different body styles and sizes. Among them was a five-passenger, US$2,500 Rambler weighing and powered by a engine.