After the first World war the company adopted a single model policy and the Forty was re-introduced with a 6.2-litre overhead-cam engine in unit with a 3-speed gearbox still using epicyclic gears and a worm drive rear axle. It was very expensive, dearer than a Rolls-Royce Silver Ghost and to maintain production a smaller car, the Twenty One joined the range in 1924. This had a 3.1-litre, six-cylinder engine, now with removable cylinder head, mated to a four-speed conventional gearbox and four-wheel brakes. It grew to the 3.3-litre Twenty Three in 1926. The Forty was finally replaced by the Thirty with straight-eight 4.4-litre engine in 1928. A further series of armoured cars was made in 1927, using a six-wheeled version of the Forty chassis.