Technical, Trials and Racing

The normal operating rpm of Thornycroft cars, in common with others of their time, was very low - little more than the idling speed of a modern car. Not surprisingly, the power outputs of car engines of the period were very low relative to engine size. Confusion reigned among the uninitiated about the true meaning of the term 'horsepower' when talking about a car's output. Engine hp was often quoted according to an RAC formula based on the cylinder diameter. Initially, the RAC hp rating was fairly accurate in terms of the actual power developed, but, as engine design advanced, the RAC formula became obsolete and was simply used to determine the amount of road tax to be paid by the owner. The above issues are discussed in these pages, with illustrations.

Thornycroft recognised the importance of publicity to be gained from winning competitive events, and, among other things, Thornycroft cars were entered for TT Races on the Isle of Man in 1905, 1906 and 1907. Thornycroft's part in competition motoring is described in these pages, in terms of drivers, cars, opposition, results and technical issues.

Information for these pages comes from contemporary Thornycroft data sources, as well as contemporary copies of The Car, The Automotor Journal, The Autocar and The Motor.