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 comparison report of a modified 20/25 HP trials touring car against an older model, noting improvements and outstanding faults.
| Identifier | ExFiles\Box 107\1\ scan0026 | |
| Date | 22th July 1930 | |
| Er...from PN.{Mr Northey} Copy to Wor.{Arthur Wormald - General Works Manager} Hs.{Lord Ernest Hives - Chair} Wr. x7960 FN.1/WT22.7.30. GXO-15. This is the open 20/25 H.P. trials touring car which recently we had converted to the latest modifications, higher compression etc. This is the first opportunity I have had of forming an opinion as to its performance in the open country. I was fortunately able to borrow Mr. Gryll's 20/25 H.P. car which is a good example of its type, in order to make some comparative tests, and I may say I was very much pleased, not only with the definite improvement in performance, but in the fact that the later type was much pleasanter to drive from the point of view of the almost complete absence of engine vibration when picking up. Two examples will illustrate the difference in performance. 1. A hill which brought the older car down to 33 m.p.h. and required a change into 3rd to maintain this speed, had the effect only of bringing the later type car down to 43 m.p.h., and consequently did not require a gear-change. 2. On a straight flat road, favourable for speed, the older car reached 61 m.p.h. and maintained it, the later car reached 70 and 71 m.p.h. The acceleration of the later car was extremely satisfactory, and showed a marked improvement, especially at the higher engine speeds on third-gear. It was to be noted that owing to the insufficient damping of the front axle (shock absorbers) the later car, when running at 70 m.p.h. was not at all stable on the road and required considerably more attention than is desirable. There is one serious fault which must be remedied, a fault which Cx.{Major Len W. Cox - Advertising Manager} already has referred to after his run recently on this car. I refer to the loud hiss like an escape of steam which can be heard from the exhaust, apparently from the nozzle whenever the car is passing between hedges or a wall, or momentarily when it passes another vehicle. The amount of hiss is excessive. I am not able to judge at the moment to what extent this is being experienced on the latest 20/25 H.P. chassis coming through from Derby, but I | ||