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).
Car performance, HP curves, and speedometer accuracy from external tests.
| Identifier | ExFiles\Box 23\4\ Scan051 | |
| Date | 21th March 1925 | |
| R.R. 493a (50m) (D.B. 175 25-9-24) J.H.D. EXPERIMENTAL REPORT. -2- Expl. No. REF: 21.3.25. the result of a straight line 'A' and a curve of the shape of 'B' being inevitably concave. As concave H.P. curves usually exist for, at the most, a few hundred r.p.m. in a touring car engine, we deduce that constant acceleration up to 60 m.p.h. is impossible, for the Renault or any other car. The other point is that the engine would require infinitely more H.P. than even the makers claim if the performance of the car as given by 'The Motor' is to be substantiated. As a point of interest we note that the car tested by 'The Autocar' was the same one as that on which 'the Motor' tests were carried out. Unless, therefore, the speedometer has been changed in the interim, we should say that the figures we have been criticising were probably taken with a speedometer which was 11 1/4% fast. Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} | ||