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).
Letter from the Experimental Dept. responding to queries on tractive and wind resistance.
| Identifier | ExFiles\Box 160\2\ scan0135 | |
| Date | 7th July 1933 | |
| C. to Rg.{Mr Rowledge} Experimental Dept. Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson}1/KT. July 7th 1933. Mr. D.{John DeLooze - Company Secretary} S. Anderson, Birmingham Central Technical College, Suffolk Street, Birmingham. Dear Sir, Mr. Rowledge has handed your letter of the 21st. June to this Dept. With reference to your queries :- (1) The tractive resistance of a car running in neutral on an average macadam road is approx. 30 lbs/ton, with normal tyre pressures. The internal engine friction varies very widely as it is directly proportional to the axle ratio used. However, for one of our cars, geared to about 3½/1 on top gear, with a big 6-cyl. engine, the figure comes out between 25 and 30 lbs/ton. (2) Some figures we have recently taken on a close-coupled saloon car, having the minimum amount of head room permissible, but incorporating a sunshine roof, give a value for K.{Mr Kilner} of .00180. It may interest you to know that an open touring body on the same chassis gives very little, if any, reduction in total wind resistance. Yours faithfully, FOR ROLLS-ROYCE LIMITED. | ||