At the time the Wolseley company was sliding into bankruptcy, William Morris was particularly interested in producing a light six-cylinder car to replicate his success with four-cylinder cars. At Olympia and at the Glasgow Exhibition he noted with interest the latest such car offered by the Wolseley company. This model, the 16/45, also known as Silent Six, was one of the factors in Morris’s decision to purchase the Wolseley company for £730,000.

After Morris purchased the company, the 16/45 hp Silent-Six continued in production, and a four-cylinder version, the 12/32 hp, was introduced, these being followed shortly afterwards by an eight-cylinder model, the 21/60 hp. The engines of these three models were similar in general design, all having an overhead camshaft driven by a vertical shaft, derived from a Hispano-Suiza design. This became a characteristic feature of Wolseley engines for a number of years. The 16/45 was available with saloon or touring coachwork. Powered by an OHC engine of 2,025cc, it was to prove a successful model.

The Viper, also of 16 hp, replaced the 16/45 in 1930. The main differences between the two cars was that the Viper had twin S.U. carburettors, hydraulic brakes, a three speed gearbox and coil ignition as opposed to the 16/45’s one carburettor, mechanical brakes, four speed gearbox and magneto. The Viper had a multi-bearing 6-cylinder engine and very complete equipment for its day. The fabric and coach-built saloons of these types sold respectively at £285 and £299.

The Viper fabric saloon had four doors, the front seats were of the bucket type and independently adjustable and the rear seat, which was deep and wide, had upholstered armrests. There were six side windows, those in the doors having sliding panels and there was safety glass used throughout. There was a blind over the rear window that could be worked by the driver. All outside bright parts were chromium plated. The equipment included electrically operated dip and switch headlights, combined tail and stop light, wire wheels, bumpers front and back, thermostatically operated radiator shutters, a calormeter and mascot. Inside there were such fittings as a roof ventilator, a parcel net, and ash-trays. Included in the instruments in the panel in front of the driver was an electric petrol gauge. A scuttle ventilator was also fitted. In the coach-built saloon, which could accommodate five persons, the glasses of the windows were worked by winding handles, and a tinted glass sun visor was added.

The engine of the Viper was similar to the original 16-45 horsepower Wolseley, being 65mm and 101mm bore and stroke, and 2,025cc capacity. A contemporary newspaper report described the engine as being accessibly designed and running sweetly and quietly. The crankshaft worked in seven bearings. Both valves and camshaft are overhead, with the camshaft being driven by a spiral bevel gear. Ignition was by battery and coil, there wais high-pressure lubrication and two oil cleaners and the petrol was drawn from the rear mounted 12-gallon tank by an autovac. Water circulated naturally to a large film block radiator, assisted by an impeller. The single plate clutch and three-speed centrally mounted gearbox formed a unit with the 6-cylinder engine, the whole being mounted on rubber.

Overall in the coach-built and fabric saloons was 5ft 11in and 5ft 9in respectively. The length over the bumpers was just over 14ft 4in, and the overall width 5ft 8in.

9,958 of these cars were produced. In 1933 by a new model known as the Wolseley Sixteen replaced the Viper.