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).
Summarizing the results of experiments on two 25 HP cars, detailing performance and smoothness work.
| Identifier | Morton\M13.2\ img092 | |
| Date | 29th August 1931 | |
| To R.{Sir Henry Royce} From Hs.{Lord Ernest Hives - Chair} c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} ORIGINAL Hs.{Lord Ernest Hives - Chair}3/M/J.29.8.31. x.5770. 25 HP. CAR. Our experiments on the 25 HP. car have been carried out on two cars. On 12-G4 which we have had at Brooklands we have gone out for performance, and on 18-G4 the work carried out has been to increase smoothness and reduce vibration. The results now justify incorporating all the good features on one car and these are being fitted to 18-G4 which has an enclosed body. The parts which are being used are all within reach for production, most of them can be made from existing material. We expect to have this car ready in about a week or ten days. Hs.{Lord Ernest Hives - Chair} | ||