The Austin 15/20 is a car from British Motor Corporation, built from 1906, when a car was a rich man's adventure and every maker was a workshop. Under the bonnet: 4399 cc 4-cylinder.
The background
The Austin 15-20 (or 15-20 hp) is the smaller-engined of the almost identical pair of new cars announced by Herbert Austin in February 1906. A very complete catalogue with detailed specifications was issued at the same time. As well as the engine's smaller bore the 15-20 differed from the 25-30 by being only available with a live rear axle and not chain-drive.
Otherwise the specifications were the same, the very minor differences are detailed below. Only four cars were manufactured. It was replaced by the 18-24 in 1907.
The engineering
Power comes from 4399 cc 4-cylinder. It weighs 864 kgfour-speed gearbox. It shifts through a four-speed gearbox. The wheelbase is 2972 mmfour-speed gearbox. These are manufacturer figures carried by Wikipedia and Wikidata, not road-test measurements.
Where it sits
Its family tree is legible: it took over from the None; assembly was at Longbridge plant, Birmingham. Its contemporaries in the catalogue — the Ford Model T, the Oldsmobile Model S, the Panhard & Levassor type U 1 coupé-chauffeur — show what else the money bought that year. Its British Motor Corporation stablemates include the Austin 10 and the Austin 12.
What it costs now
There is no federal ownership record for the Austin 15/20 — it predates the complaint database or was never sold in the United States — so MotorJury publishes no running-cost figure for it. For a car of this age the price is set by the collector market and the condition of the individual example, not by a formula.