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).
With graphs comparing vehicle acceleration against road speed for different models.
| Identifier | ExFiles\Box 69\4\ scan0309 | |
| Date | 14th December 1925 | |
| R.R. 493a (50 H) (D.D. 31. 12-6-25) J.H.D. EXPERIMENTAL REPORT. -4- Expl. No. REF: He/Re/LG14.12.25 GRAPH 1. Accn Ft./Sec.2 ROAD SPEED. M.P.H. SUMMERS' PHANTOM 117MC. STANDARD PHANTOM 98NK. Individual readings only given for 117-MC. thus x these shew the rather erratic nature of the test. We have taken the mean of all the figures for the Phantom acceleration. Those opposite the Vauxhall figures in the report are poor, those given from 10 m.p.h. are unusually good. GRAPH II. Accn Ft./Sec.2 ROAD SPEED. M.P.H. VAUXHALL 117-M.C. Individual readings only given for Vauxhall. Thus ☉ | ||