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).
Power output graph comparing a 25/30 HP engine's performance with both an open exhaust and a complete system, against a 5.7 C/R Buick Series 40 engine.
| Identifier | ExFiles\Box 104\2\ scan0274 | |
| Date | 15th October 1937 guessed | |
| 523 25/30 HP ROLLS-ROYCE POWER OUTPUT ① OPEN EXHAUST ② WITH COMPLETE EXHAUST SYSTEM. B.H.P. B.M.E.P. R.P.M. 5.7 C/R BUICK SERIES 40 FITTED WITH COMPLETE EXHAUST SYSTEM C.T.S. | ||