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).
Comparison table of car specifications and performance data from hill climb tests.
| Identifier | ExFiles\Box 5a\5\ 05-page096 | |
| Date | 20th June 1938 guessed | |
| CAR. | 12-G4. | 12-G4. | 14-G4. | 17-G4. | Chrysler. | 21-EX. Engine. | Std. 20 HP. | .2" on bore R = 5.25/1 14% larger car. | R = 5/1 Turbulent head. | Std. 20 HP. | '75' | S.S. Capacity C.C. | 3127 | 3558 | 3127 | 3127 | 4079 | 7668 Eng. revs per mile top gear. | 3069 | 3008 | 3069 | 3021 | 2708 | 2286 Tyres and wheels. | 31 X 6, 19" rims. Triple stud tread. | 31 X 6, 19" rims. Silent tread fort. | 31 X 6 19" rims. Triple stud trd. | 31 X 6 19" rims. Triple stud fort. | | 33 X 6.75 Silent tread. Weight. | 33-3-7 | 31-1-7 | 34-0-0 | 34-3-14 | 52-2-21 | 48-1-7 Litres/ton/mile. | 5676 | 6826 | 5645 | 5417 | 6757 | 7256 Staunton Hill. | 10 MPH. | 10 MPH. | 10 MPH. | 10 MPH. | 10 MPH. | Pin:MPH. | 19 * | 30 * | 18 * | 16 * | 29 * | Time secs. | 32 * | 20.4 | 34.6 | 36.4 | 23.8 | Ticknall Hill. | 10 * | 10 * | 10 * | 10 * | 10 * | 10 MPH. Gate. | 26.5 | 33 | 29 | 25 * | 32 | 31 * Pin:MPH. | 43 * | 47 * | 48 * | 44 * | 55 * | 60 * Time secs. | 79 | 62 | 71.4 | 80.4 | 54.2 | 58.8 Fustern Hill. | 10 * | Too fast to drive up this hill. | 10 * | 10 * | | Max:MPH. | 41 * | | 44 * | 40 * | | Min:MPH. | 17 * | | 23 | 14 | | Time secs. | 112.4 | | 100 | 122 | | Fustern Hill. | | 10 MPH. | | | 10 MPH. | 10 MPH. MPH. Δ | | 32 * | | | 29 * | 30 Finish. | | 37 * | | | 35 * | 35.5 Time secs. | | 60 secs. | | | 58.8 | 63.2 | ||