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).
Graph showing results of tractive resistance versus speed tests conducted at Brooklands.
| Identifier | ExFiles\Box 155\1\ scan0320 | |
| Date | 25th June 1937 | |
| 25-6-37 TESTS AT BROOKLANDS 39 EX 5250 lbs 32 EX 5978 lbs OLJS 3498 lbs TRACTIVE RESISTANCE lbs / TON SPEED M P H 39 EX 32 EX OLJS | ||