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 results of a 2942-mile road test of 7.5' tyres on a Phantom III vehicle.
| Identifier | ExFiles\Box 158\1\ scan0180 | |
| Date | 25th April 1938 | |
| 1339. GRY {Shadwell Grylls} S/W. {Sales / Derby Works} Rm. {William Robotham - Chief Engineer} 7.5" tyres on Phantom III. Cx {Major Len W. Cox - Advertising Manager} 5/KW25.4.38. You will remember that it was arranged I should run a set of tyres of this size on the car I was using, and I did so until the car was sold last week. Checking up the figures I find I ran them 2942 miles. They were removed before the car was handed over to the customer. During that time I found no occasion to criticise them adversely in any way. The difference in the heaviness of the steering was so slight as to be almost unnoticeable so long as the pressures were kept up to normal. If you are wanting some tyres for further experimental work and could make use of these, which are only about 25% worn, perhaps you will let me know. Otherwise, we shall keep them at LH {Mr Haworth} in the hope that a further opportunity of using them still more will occur later. Cx. {Major Len W. Cox - Advertising Manager} hieb | ||