During 1906 Royce had been developing an improved six-cylinder model with more power than the 30hp.
This series was a success and was followed by a six-cylinder model.
From 1912, six-cylinder models were made upon individual orders only.
A six-cylinder model was added to the range in 1914.
The company built four- and six-cylinder models until 1919.
The six-cylinder model grew to 6 L in 1908.
A new six-cylinder model, named AM 80 came in 1928.
The sporting six-cylinder models had a great racing history.
In 1927 a six-cylinder model with 1557 cc engine was added to the range.
A six-cylinder model was able to produce 166,000 16-page newspapers per hour.