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).
Car acceleration in relation to weight and engine power, with graphs.
| Identifier | ExFiles\Box 39\2\ Scan207 | |
| Date | 12th October 1925 | |
| EXPERIMENTAL REPORT. -2- Expl. No. (1) ACCELERATION. (a) Direct drive - car weight. The acceleration of two cars which are otherwise exactly similar will be inversely proportional to their weights throughout the whole range of their speeds. That is if one car weighing 2 tons has at 20 m.p.h. an acceleration of 3 ft/sec², an exactly similar car weighing one ton will have an acceleration of 6 ft/sec², at that speed. Axle ratio - engine power. The acceleration of a car does not improve in direction proportion to its increase in engine power or lower gear ratio. At low speeds (up to 30 mph.) the improved acceleration will be very nearly proportional to the increase in engine power. At high speeds, however, a 20% increase in engine power may produce a 30% increase in accrn. On A.{Mr Adams} B. New H.P. 16 Old H.P. 13 % power gain 23% Power to drive car 2 HP, available for acceleration :- New H.P. 14 Old H.P. 11 % gain in accrn. 27.3% In the same way on X. Y. % gain in power 17½% % gain in accrn. 30% contd :- | ||