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).
Table of acceleration and speed test results under various car configurations and axle ratios.
| Identifier | ExFiles\Box 29\3\ Scan080 | |
| Date | 9th February 1937 | |
| Acceleration. Test No. | Condition of Car. | Compression. | 10 to 60 MPH. axle ratio 15 x 52 | top gear. axle ratio 16 x 52 | 1/4 mile flying start. axle ratio 15 x 52 | Axle ratio 16 x 52 | Lap speed. Axle ratio 15 x 52 | Axle ratio 16 X 52. --- | --- | --- | --- | --- | --- | --- | --- | --- 1. | Hood down, screen down, cutout open. | High | 20 secs. | 26 secs. | 78.26 MPH | 78.26 MPH | 73.24 MPH | 73.24 MPH 2. | Same as No.1 cutout closed | High | 23 " | 29 " | 70.59 " | 73.47 " | 69.66 " | 68.69 " 3. | Same as No.1 cutout open | 1/8" liners under cylinder | 23 " & | 28 " | 74.07 " | 75.0 " | 72.18 " | 72.18 " 4. | Same as No.1 cutout closed. Y | " " | 25 " | 32 " | 69.23 " | 70.59 " | 68.22 " | 68.22 " 5. | Windscreen up, hood down, cutout open | High | --- | 26 " | 75.0 " | 75.0 " | 72.18 " | 71.15 " 6. | Same as No.5. | 1/8" liners under cylinder. | --- | 28 " | 75.0 " | 72.0 " | >70.64 " | 70.14 " 7. | Windscreen and hood up, cutout open. | High | 21 " | 28 " | 75.0 " | 73.47 " | 71.66 " | 70.14 " 8. | Same as No. 7. | 1/8" liners under cylinder. | 23 " | 30 " | 72.0 " | 72.0 " | 70.64 " | 69.66 " 9. | Same as No. 7, cutout closed. | High | 24 " | 30 " | 69.23 " | 72.0 " | 69.30 " | 66.39 " 10. | Same as No. 7, cutout closed. | 1/8" liners under cylinder. | 25 " | 32 " | 69.23 " | 69.23 " | 66.85 " | 65.10" Side text: R.R. 199 (25M) (SD626 9-2-37) MP 180805 | ||