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).
Carburation and petrol consumption tests on car 49-GB, comparing pre-war and post-war petrol quality.
| Identifier | ExFiles\Box 183\M22\ img033 | |
| Date | 1st February 1919 | |
| X3056 49GB To R.{Sir Henry Royce} from EH. c. to CJ. c. to E.{Mr Elliott - Chief Engineer} cx{Major Len W. Cox - Advertising Manager} to By.{R.W. Bailey - Chief Engineer} EH7/LG4. 2.19. X.2631. - TESTS ON 49-GB. - X.2768. X.2784. X.3056. We have been carrying out several tests on 49-GB with the carburation. We found that we could get no decent running from this car during the cold weather which we have had lately. The petrol is undoubtedly poor but I suppose it is what we have to expect. We found the water temperature of this car when running from 30 to 35 m.p.h. with the atmospheric temperature anything from 3° C to zero, was never above 40°C. Under these conditions we tried the difference between the petrol we are receiving now and some petrol which we have had since before the war. The difference in the pre-war petrol and the present petrol is remarkable. The only way in which we could get any reasonable results from the present petrol was to keep the water temperature high, to get decent running it had to be about 80°C. When the water is at this temperature the difference between the pre-war spirit and the present spirit is not nearly so marked. We made a test on the road and found with the present petrol with the water at 40°C the best consumption was 12 m.p.g. in the same condition with the water at 80°C we could obtain 15 m.p.g. Contd. | ||