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).
Test report on the performance of car model 1.EX after a 300-mile drive, covering speed, handling, tyres, and fuel consumption.
| Identifier | Morton\M22\ img066 | |
| Date | 10th August 1920 | |
| R.R. 199 (250T) (SD676 19-7-17) MP 180865 [Handwritten Annotation] PWW1. 40/50 R's FIRST REACTIONS TO 1 EX. (SECOND TIME ROUND?) To Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} c. to Da.{Bernard Day - Chassis Design} c. to CJ. c. to PN.{Mr Northey} R24/H10.8.20. X.3763. re 1.EX. I have run this 300 miles and I am very pleased with it, from every point of view it seems the best car I have ever had. Speeds of 70 been touched many times, and for quietly sliding through towns, it is delightful. It is therefore smooth and quiet and fast. There is only the reaction vibration that one can complain about. This is manifest because it pulls so extremely vigorously over a range of speed from the veriest crawl upwards. X.4050. The American tyres/ [handwritten: seem] remarkably good. They were pumped to 75 lbs. ", before starting, and the car seemed to run remarkably freely, with a consumption of 18 M.P.G. at a good speed, averaging 45 all through a long journey, but [handwritten: 40 with 50 & 60 on a few occasions] generally the car was running 70 as above. The miles were correctly indicated, (counted) and agreed to 1% of the mile stones, but the petrol was measured by gauge stick, (which please check). The total average load is two tons. Now doubt soft tyres would make the hold of the road better, at corners where pot holes abound, but my hard tyres are better and safer for touring, and probably are considerably cheaper to run for tyres and petrol, (this should be confirmed) I also think there is much less risk of side-slip on grease. | ||