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 graph showing fuel consumption versus speed for a 4-cycle CI lorry engine.
| Identifier | ExFiles\Box 179b\3\ img173 | |
| Date | 7th February 1933 guessed | |
| FIG. 5 CI LORRY ENGINE WITH CHAMBER E 6.55" - 4 CYCLE FUEL CONSUMPTION SPEED (R.P.M) 1000 1200 1400 | ||