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 log for Dunlop straight-sided tyres detailing daily mileage and routes taken.
| Identifier | ExFiles\Box 45\1\ Scan040 | |
| Date | 20th June 1920 | |
| X.4050 Tests on Dunlop straight-sided tyres for week ending - Particulars of Car - R.R. 40/50 - fitted with double limousine body, Wire wheels, Goodyear rims. Weight - Rear 1 ton. 7 cwt. Front 1 " 1 " Tyre pressures 80 lbs in rear - 65 lbs. in the front. Date. | Tyres fitted. | Position on Car. | Total miles run. | Daily miles. | Route taken. | Remarks. 15.6.20 | FD.{Frank Dodd - Bodies}2012 | O rear | 20 | 20 | Local runs. | ----------- | FD.{Frank Dodd - Bodies}3168 | N rear | 20 | 20 | " | " | FD.{Frank Dodd - Bodies}1908 | O front | " | " | " | " | FD.{Frank Dodd - Bodies}1648 | N " | " | " | " | " 16.6.20 | FD.{Frank Dodd - Bodies}2012 | O rear | 52 | 32 | Local runs. | ----------- | FD.{Frank Dodd - Bodies}3168 | N rear | " | " | " | " | FD.{Frank Dodd - Bodies}1908 | O front | " | " | " | " | FD.{Frank Dodd - Bodies}1648 | N " | " | " | " | " 17.6.20 | FD.{Frank Dodd - Bodies}2012 | O rear | 232 | 180 | Derby to Leeds and back. | Average speed 32 M.P.H. | FD.{Frank Dodd - Bodies}3168 | N rear | " | " | " | | FD.{Frank Dodd - Bodies}1908 | O front | " | " | " | | FD.{Frank Dodd - Bodies}1648 | N " | " | " | " | 18.6.20 | FD.{Frank Dodd - Bodies}2012 | O rear | 412 | 180 | Derby to Leeds and back | Average speed 30 M.P.H. | FD.{Frank Dodd - Bodies}3168 | N rear | " | " | " | | FD.{Frank Dodd - Bodies}1908 | O front | " | " | " | | FD.{Frank Dodd - Bodies}1648 | N " | " | " | " | 19.6.20 | FD.{Frank Dodd - Bodies}2012 | O rear | 590 | 178 | Derby, Mansfield, Nottingham and district. | 20.6.20 | FD.{Frank Dodd - Bodies}3168 | N rear | " | " | " | | FD.{Frank Dodd - Bodies}1908 | O front | " | " | " | | FD.{Frank Dodd - Bodies}1648 | N " | " | " | " | R.R. 199 (2501) (SD3076) 16-2-(17) MP1600S | ||