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).
Comparative speed test report for cars 18-G-IV and 20-G-IV at Brooklands track.
| Identifier | ExFiles\Box 155\1\ scan0163 | |
| Date | 19th September 1934 | |
| To Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} x783 Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager}12/KW.19.9.34. 18-G-IV and 20-G-IV. The above two cars were taken down yesterday to Brooklands track for comparative speed tests, 18-G-IV being fitted with a standard exhaust system and 20-G-IV fitted with our exhaust system to Hs.{Lord Ernest Hives - Chair}1436 and Hs.{Lord Ernest Hives - Chair}1514. The respective performances were as follows :- 18-G-IV. 20-G-IV. Lap Speed 66.58 M.P.H. 71.35 M.P.H. 66.76 " 71.25 " Both cars starting side by side at 10 M.P.H. in Top Gear. 20-G-IV gained ¼ car length at 30 M.P.H., 1 length at 40 M.P.H., 1½ lengths at 50 M.P.H., 3 lengths at 60 M.P.H. and approx. 70-80 yards at the end of 1 lap. Hs{Lord Ernest Hives - Chair}/Wym.{G. Harold Whyman - Experimental Manager} | ||