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 of 20 HP cars using various brands of petrol, detailing hill climb and level speed test results.
| Identifier | WestWitteringFiles\K\October1923\ Scan89 | |
| Date | 1st October 1923 guessed | |
| COMPARISON OF PERFORMANCE ON 20 HP. CARS - 4-G-11 - 3-G-11 AND 79-AO. (10.000 MILES TEST CAR) - WITH VARIOUS BRANDS OF PETROL. Chassis No. Test. Shell No.1. Shell Mex. Red Line. 4-G-11. Time on hill in secs. 117 117.5 114 Max. speed on hill. M.P.H. 39 39 40 Min. speed on hill. M.P.H. 15 15.5 16.5 3-G-11. Time on hill in secs. 109.5 110.5 110 Max. speed on hill. M.P.H. 39.75 38.75 39.5 Min. speed on hill. M.P.H. 19.75 19 19.5 79-AO. Time on hill in secs. 124 133 120 Max. speed on hill. M.P.H. 39 38.5 38.25 Min. speed on hill. M.P.H. 14 11 15 MAXIMUM SPEED ON LEVEL IN 700 YDS. STARTING AT 40 M.P.H. AVERAGE OF TESTS. 4-G-11. Speed test. 55.6 55.9 55.1 3-G-11. " " 54.5 53.75 54.25 79-AO. " " 55 54.5 55.5 | ||