The Armstrong Siddeley 15 HP

Production period	1927 to 1934
Number of cars produced	7,203
Engine	6 cylinder, 1900cc, 15HP
Body styles	(See below)
Transmission	Manual Pre-selector

The 15HP was produced between 1927 and 1934, with a total production of 7,203 vehicles (which includes the 15/16).

The 15HP was first introduced in 1927 and continued in production until 1934 when it was replaced by the 17HP. The six cylinder 1900cc engine had a bore/stroke of 63.5mm x 101mm. The speed range in top gear was from 5mph to 50mph with a petrol consumption of 24mpg.

The chasis was similar to the 14HP with a wheelbase of 9’ 6”, a track of 4’ 8” and an overall length of 13’ 2” and was priced at £270. Tyre life was reckoned to be 10,000 miles. Decarbonising needed to be carried out every 15,000 miles.

Power output was increased in 1930 along with a new chassis. A four speed preselector gearbox at an extra cost of £40 was an option to the standard three speed normal gearbox.

1931 saw the introduction of the famous V-Radiator. A Short 15 vehicle with a wheelbase at 9’ 1” was introduced and the Normal 15 wheelbase was increased by 1” to 9’ 7”. The three speed preselector gearbox was now standard on the Short 15 and the four speed preselector gearbox was now fitted as standard to the Normal 15.

In 1932 a normal belt driven fan was fited to replace the vaned flywheel and the engine bonnet had vertical louvres added to assist cooling. The engine capacity was increased by lengthening the stroke to 114mm and the car was then known as the 15/40. Top speed now exceeded 60mph.

Various bodies were available: 2 or 5 Seater Tourers, Fabric Saloon, Coachbuilt Saloon and a Foursome Coupe with a sliding roof. Cars sold in Australia were mainly the long chassis model with Australian coachwork and were priced locally at AU£695 + sales tax.