The first two models, the 40 and 41, debuted in 1916. Two body styles, a five-passenger touring car and three-passenger roadster, were offered for the Model 40, while the Model 41 was sold as a seven-passenger saloon. Both Model 40 variants were sold for $1985 ($41,790 in 2012 dollars), and the Model 41 was offered for a price of $2085 ($43,896 in 2012 dollars). Both models were fitted with 5840cc V12 engines capable of generating 60 bhp (44 kW) of power and featured three-speed manual transmission. The wheelbase of the 1916 models measured 3226 mm (127 in).
The reputation of the vehicle greatened in 1917, when American racecar driver Percy Ford won that year's Chicago dealer's race while driving a 1916 Light 12 at an average speed of 143 km/h (89 mph).
A new model of the Light 12 was introduced in 1917, and was sold until 1919. It featured a V12 engine capable of generating 36.3 bhp (27 kW) of power. Like the preceding models, it rode on a wheelbase of 3226 mm (127 in).
The Haynes 46 Light 12 debuted in 1920. It was sold as a seven-passenger touring car, four-passenger roadster, four-passenger coupe, and seven-passenger saloon. It featured a V12 engine capable of 62 bhp (46 kW) of power, as well as three-speed manual transmission. The Model 46 rode on a wheelbase of 3226 mm (127 in).
The Model 48 was sold from 1921 to 1922. Six body styles of the vehicle were offered, and the 48 was sold for a price of anywhere from $3450 to $4950, depending on the selected body style. The rear-wheel drive Model 48 was fitted with a 5840cc V12 engine capable of generating 70 bhp (52 kW) of power. It rode on a 3353 mm (132 in) wheelbase.