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).
Comparative data sheet of two R.A.C. tests between a Napier and a Rolls-Royce vehicle.
| Identifier | ExFiles\Box 81\1\ scan0049 | |
| Date | 1st June 1920 guessed | |
| Particulars of two R.A.C Tests. [Column 1: Parameters] Route taken Petrol consumption Speed on Brooklands Windage Total weight with} passengers Gear Ratio Bore and stroke of} engine R.A.C. rating [Column 2: 6-cylinder Napier 59.9 h.p R.A.C. Rating.] London to Lands End to John O'Groats to Edinburgh and back to London 23.9 m.p.g. 53.2 ton m.p.g. 77.1. m.p.h. 10.3 sq. feet. 4990 lbs. 3 to 1. 5 x 5 inches. 59.9 H.P. [Column 3: 6-cylinder Rolls-Royce 48.6h.p. R.A.C.Rating.] London to Edinburgh and back. 24.32 m.p.g. +1.75% 57.07 ton m.p.g. +7.25% 78.26 m.p.h. +1.5% 13.01 sq. feet. 26.3% 5257 lbs. 5.35% 2.9 to 1 3.5% 4½ x 4½ inches. 11% 48.6 H.P. 23.25% [Handwritten Calculations] .42 / 1.75% 3.87 - 7.25% 1.16 - 1.5% 2.71 26.3% 267 5.35% 1in 3.5% 11.3 | ||