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).
Road test data and performance figures for a Terraplane 6.
| Identifier | ExFiles\Box 21\6\ Scan192 | |
| Date | 4th February 1935 | |
| L4217 4.2.35. Terraplane 6. Gear ratios 4.11 6.58 9.73 At 40 m.p.h. speedometer reading (12% fast) in top gear, engine r.p.m. = 1834. On the road it was discovered that the maximum speedometer speed obtainable on level is 40 m.p.h. in 1st gear. By removing fan belt, torsional period was reached at 44 m.p.h. These speeds correspond to 4350 and 4800 r.p.m. Engine r.p.m. at genuine 60 m.p.h. = 3080. | ||