In November of 1907, Cadillac introduced the Model S which was a variant of their 10HP single-cylinder car. This was nearly identical to the Model M, Model S & Model T which were all essentially the same model with different body styles and wheelbases. The Model S was a two-seat Runabout body on the 82 inch wheelbase chassis.
Engineering principles for the aging single-cylinder Cadillac were similar to the very first Model A of 1903. It used a Leland & Faulconer engine, 2-speed transmission and a Brown-Lipe differential. By 1907 the power had increased from 6.5 to 10 advertised bhp.
The Model S featured larger 24 inch wheels and could be ordered with options to fit Rubber, Leather or a Victoria Style top for $60, $80 and $175 respectively. A definitive feature of the Model S was its longer wheelbase running boards.
As an available option, single and double rumble seats could be ordered with both the straight line and Victoria style runabouts.