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).
Comparison of gear ratios and related specifications for a Chevrolet and a 25/30 HP model.
| Identifier | ExFiles\Box 104\4\ scan0273 | |
| Date | 13th November 1936 | |
| To Rm.{William Robotham - Chief Engineer} > 528 13.11.36. Chevrolet and 25/30 H.P. Gear Ratios. Chevrolet. Tyre size - 6 x 16. Axle ratio - 4.1 : 1 Effective tyre circumference - 85". Road wheels. - 745.4 Engine /revs at 60 M.P.H. - 3,056. 6 25/30 Tyre size - 6 x 19. Axle ratio - 4.55 : 1 Effective tyre circum. 94.875". Road wheels./Rev. mile - 667.9. Engine/revs/ at 60 M.P.H. - 3,040. Rm{William Robotham - Chief Engineer}/F.Dodd. | ||