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 table of radiator face area, volume, and on-track temperature for various car models.
| Identifier | WestWitteringFiles\U\August1930-November1930\ Scan027 | |
| Date | 26th August 1930 guessed | |
| CAR. | Face Area per 1000 litre disp. per mile. ROLLS-ROYCE 25 HP. | 83.0 sq.ins. CHRYSLER 75. | 82.7 sq.ins. HISPANO. | 77.3 sq.ins. ROLLS-ROYCE 40/50. | 71.2 sq.ins. GRAHAM PAIGE. | 65.2 MARMON | 63.0 PIERCE ARROW | 54.4 CAR. | Volume per 1000 litre disp. per mile. ROLLS-ROYCE 25 HP. | 308. HISPANO. | 308. ROLLS-ROYCE 40/50. | 265. GRAHAM PAIGE. | 220. CHRYSLER 75. | 207. MARMON | 173. PIERCE ARROW. | 129.2 CAR. | Temp. at 60 M.P.H. on Track. ROLLS-ROYCE 40/50. Vent. Bonnet | 71°C. CHRYSLER. | 73° C. HISPANO. | 74° C. GRAHAM PAIGE. | 77° C. PIERCE ARROW | 82° C. MARMON | 85° C. Engine tightening up. 25 HP. ROLLS-ROYCE. | Not yet recorded. HS{Lord Ernest Hives - Chair}/An. | ||