The Hillman 12/15 was a car produced between 1908 and 1913.
The cars were fitted with a 2.3 litre engine designed by Frenchman Louis Coatalen. The camshaft is extremely robust for the size of engine and period, it is set on three main bearings with the centre one being heavily webbed. Lubrication was a rather half-hearted compromise between pressure and gravity feed. Ignition was normally by accumulator and coil, but a Bosch high-tension magneto could be added for an additional £20. The engine produced about 20bhp, which was mated to a three-speed gearbox via a leather cone clutch. The top speed of the 12/15 was around 40mph with the engine topping out 2000rpm.
The 12/15 measures 1.7 metres wide, 3.45 metres long and has a wheelbase of 2.44 metres.
Only two examples of the 12/15 exist to the present day.