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).
Report discussing tyre wear issues and the effect of tyre inflation pressure on petrol consumption, including a performance graph.
Identifier | ExFiles\Box 53\3\ Scan007 | |
Date | 6th 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. [Start of chart section] TYRE INFLATION PRESSURE EFFECT OF SPEED & TYRE PRESSURE ON PET. CONSUMPTION WATER TEMP 60° C IGNITION STANDARD MIXTURE CONTROL CENTRAL AXLE 15 x 52 TYRES STANDARD Graph data: Y-axis: MPG / PET. CONS (from 12 to 20) X-axis: ROAD SPEED MPH (from 10 to 50) Line 1 (dashed): 60 Lbs/sq in Line 2 (solid): 25 Lbs/sq in [End of chart section] 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 :- | ||