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).
The effect of tyre types and inflation pressure on petrol consumption, with an accompanying graph.
| Identifier | ExFiles\Box 45\2\ Scan008 | |
| Date | 1st January 1927 guessed | |
| contd :- -6- tread makes the tyre ride very harshly when new. In addition, on the Rapson double-tread tyre, when the first tread is finished, it comes off in a series of large pieces which hit the wings of the car and make a tremendous noise. As this continues for many miles it is rather a distressing feature. III: PETROL CONSUMPTION AND TYRES. (a) The effect of balloon tyres on consumption. Balloon tyres are often accused of causing a considerable increase in petrol consumption. We give the results of a test carried out on cord tyres shewing the measured difference in consumption when these are run first at an absurdly high, and then at an exceptionally low inflation pressure. [Graph Section] TITLE: TYRE INFLATION PRESSURE [Test Conditions Table] EFFECT OF SPEED & TYRE PRESSURE ON PET. CONSUMPTION WATER TEMP: 80° C. IGNITION: STANDARD MIXTURE CONTROL: CENTRAL AXLE: 15 x 52 TYRES: STANDARD [Graph Axes & Data] Y-AXIS: MPG, PET. CONS X-AXIS: ROAD SPEED M.P.H DATA LINE 1 (dotted): 60 Lbs/□ DATA LINE 2 (solid): 25 Lbs/□ It will be observed that at a normal touring speed of 30 m.p.h. this amounts to about 6%. Now the difference between the rolling resistance of a normally inflated high pressure and balloon cord tyre is less than that contd :- | ||