From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Page discussing the effect of headwinds on required horsepower, with a graph showing HP to overcome wind resistance vs. road speed.
| Identifier | ExFiles\Box 160\2\ scan0093 | |
| Date | 14th June 1926 guessed | |
| contd :- -3- speed of 30 m.p.h. is only 6 HP. If on the other hand the car is originally travelling at 60 m.p.h. and a head wind of 10 m.p.h. again blows upon it, the extra H.P. necessary to keep the car going is 20 HP. In other words a 10 m.p.h. head wind at 60 m.p.h. has 3.3 times the effect of the same wind at 30 m.p.h. POWER OF WIND AT VARIOUS ROAD SPEEDS GRAPH II H.P. TO OVERCOME WIND RESISTANCE ROAD SPEED M.P.H. 30-40. 6 H.P. 60-70. 20 H.P. Hs{Lord Ernest Hives - Chair}/W. A.{Mr Adams} Robotham. | ||