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 comparison table for various cars over different measured distances.
| Identifier | WestWitteringFiles\P\October1926-November1926\ Scan026 | |
| Date | 6th October 1926 guessed | |
| CAR. | Type of body. Remarks etc. | Standing 1/4 mile. Secs. | Standing 1/4 mile. AV.MPH. | Standing 1/2 mile. Secs. | Standing 1/2 mile. AV.MPH. | Flying 1/2 mile. Secs. | Flying 1/2 mile. AV.MPH. --- | --- | --- | --- | --- | --- | --- | --- VAUXHALL. 30 - 98 HP. | 2-seater. Wings and screen. Just tuned up by Works. | 31 3/5 | 56.96 | 55 3/5 | 64.75 | 22 | 81.82 VAUXHALL. 30 - 98 HP. | 4-seater - standard 30/98 - cut away wings. | 34 1/5 | 52.63 | 57 1/5 | 62.94 | 23 | 78.26 VAUXHALL. 30 - 98 HP. | 4-seater - standard 30/98. | 34 | 52.94 | 57 4/5 | 62.28 | 23 4/5 | 75.63 ROLLS-ROYCE. 117-HC. | 4-seater - touring. No attempt at streamline. | 39 4/5 | 45.23 | 63 4/5 | 56.43 | 24 | 75 A.C. 6-CYL. 2-LITRE. | Normal 2-seater touring body. | 39 | 46.15 | 64 1/5 | 56.17 | 25 1/5 | 71.4 HISPANO-SUIZA. 37 HP. | Fairly narrow 4-seater closed body. | 38 1/5 | 47.12 | 64 | 56.25 | 25 4/5 | 69.7 LANCIA LAMBDA. | Short wheelbase 4-seater. | 43 3/5 | 41.28 | 71 3/5 | 50.28 | 28 | 64.3 | ||