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 specific capacities for Bent., 25/30, and Ph.III car engines.
| Identifier | ExFiles\Box 101\3\ scan0056 | |
| Date | 3rd May 1937 | |
| To Rm.{William Robotham - Chief Engineer} 500 3.5.37 SPECIFIC ENGINE CAPACITIES We give herewith the specific capacities of our car engines:- Bent. 25/30. Ph.III. Cap. (cu. ins) 260 260 448 Gear ratio. 4.10 4.55 4.25 Tyre size. 5.5 X 18 6 X 19 7 X 18 Effective Circ. 90.375 94.875 97.312 Weight of chassis. 33.5 38.5 52.5 Cu.ft/mile. 216.2 228 358 Cu.ft/ton/mile. 129 118.5 136.5 Rm{William Robotham - Chief Engineer}/Smth. | ||