Announced in October 1924 with a much more powerful engine than its predecessor[2] it would remain available until 1928 though "supplemented" from May 1926 by the 2.4-litre 16/50 with a strengthened transmission on the same chassis.
[3] Somewhat unconventional the new 14/45 displayed these distinctive attributes: unusual engine design (spherical combustion chambers), four-wheel brakes, four-speed gearbox[2][4] The engine was given spherical combustion chambers for which greater efficiency was claimed because it provided more even burning of the fuel and air mixture.
[2] By the time of the following Motor Show the worm drive at the rear of the engine for the camshaft and other accessories had been modified to deal with a noise problem.
[2] The reviewer for "The Times" liked the car though he did comment that the flexible and responsive engine seemed to have "no very marked bite".
Passenger accommodation back and front was "unusually comfortable" and "wholly quiet".
It had been seen previously by the public in prototype in the RAC Rally at Hastings as the competition winning Rover Speed Fourteen 4-door coupé.
Maximum power output of 48 bhp (39.7 kW) at 4,600 rpm[7] and a top speed of 111 km/h (69 mph) were claimed.
[9] The Speed engine had three semi-downdraught carburettors in place of the standard single down-draught instrument, specially streamlined ports and manifolds and a high-compression cylinder head.
[6] The Times' correspondent thought the car travelled rapidly and smoothly and found the lines of the body pleasing.
The car seemed "well-found" - two wipers with two motors, a fitted tool tray below the instrument panel, a windscreen with a handle and concealed chain for security.
Although it had the less highly tuned engine and reached just 70 mph on the straight the tester described it as fast for its size, stable on the road.
[12] An "entirely new" car was announced on 14 October 1938 with a more powerful engine, 1901 cc, new coachwork, "easy-clean" wheels and additional refinements including synchromesh on 3rd and top gears (not essential on cars with freewheel), automatic chassis lubrication and anti-roll stabilisers front and back.