Triumph MAYFLOWER 1951 Instruction Book page 7

GENERAL SPECIFICATION—Road Speed Data
DESIRABLE ENGINE SPEED LIMITS
(Particularly in gears lower than top)
The engine is capable of "revving" very fast, yet the driver should avoid continued
" over-revving," which is most likely to occur in the lower gears. We strongly
recommend that the driver shall not continually exceed the car speeds given
below which correspond to approximately 4,000 engine r.p.m.
The above speeds are given in round figures so that the owner can easily
remember them.
See page 16 for running-in speeds recommended.
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