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).
Performance data table for a Park Ward Saloon showing tractive resistance at various speeds.
| Identifier | ExFiles\Box 84\3\ scan0118 | |
| Date | 6th March 1939 guessed | |
| APPENDIX. PARK WARD SALOON 181.CW. Tyres at 34 lbs in² A = 23.2 sq.ft. Wat = 1.81 Tons. MPH. | Total Tractive Resistance. lbs. | Tr{Capt. F. W. Turner - Finance} Tyres. lbs. | Tr{Capt. F. W. Turner - Finance} Windage. lbs. | K.{Mr Kilner} ø 95 | 418 | 108.5 | 309.5 | .001475 75 | 282 | 73.4 | 208.6 | .001595 50 | 146 | 50.0 | 96.0 | .00165 25 | 71 | 47.0 | 24.0 | .00165 ø Extrapolated by extension of formula Tr{Capt. F. W. Turner - Finance} = (46 + .0413V²) Extrapolated by Andreau's formula, as below, with K = .00163. 95 | 448 | 108 | 340 | .00163 | ||