CLIMBING POWER

Rotorua Morning Post, Volume 2, Issue 251, 14 June 1932, Page 2

CLIMBING POWER

TOP-GEAR PERFORMANCE. OVER-RATED FEATURE. For some years, top-gear performance was ,so extensively advertise and used as a saies argunient, that it is little wonder many people still have a distorted idea of its value, writes a motoring expert. Actually, the ahility to climb freak hills on top gear means simply that the car is over-powered from the very practical viewpoint of economy in running, and should really he fegarded as orie of the pfivileges of the wealthy owner, or else that it i is under-geared. i Older motorists will have memories of under -powered cars which required recourse to the lower gears ..at every rise, but this type of vehicle no longer exists, even the smallest cars now ! having an adequate power-weight ra- . tio. | Probabiy the best definition of a car 1 having an all-round satisf actory performance is that it should take all i ordinary main-road hills on top gear j when driven at the average speed of 1 about thirty niiles an hour, although, j if it has a modern silent-third type of gear-box, slightly improved speed should he given on the third gear over the steeper grades. Comfortable traffic performance, with a safe margin. of acceleration, should be given in third gear. With the better class of cars it is possible to make the mistake of staying in third in mistake for top gear. Extreme top-gear performance is usually bought dearly at the expense of fitting an unnecessarily large engine, an unnecessarily low top-gear ratio, or a combination of both. In every case it is extravagant. If the engine is too large fuel and oil consumption will suffer, and the freedom from repairs due to the engine always working well below its maximum be found to be largely imaginary. "Fussy" Engines.

If, on the other hand, the engine is of reasonable size, but the top-gear ratio is low, the number of revolutions > per mile and per minute will be increased to an undesirable degree. The j engine will be "fussy" at ordinary j speeds, may require more attention, j will have a higher fuel and oil con- j sumption than it should, and the maximum road speed of the car, both on top and the lower gears, will he unreasonahly low. | Although American manufacturers were the first to make use of the "top gear, every where" argument, their re- j cent productions show that the error | is being rectified. The rapid adoption j within recent years of synehro-mesh gear-boxes and silent thirds, dsvices j which are aimed at encou.-agiii.g in- 1 expert drivers to change gear when necessary, are evidence of this; while rapid development in Britain and on the Continent of automatic gear- i ichanging devices indicates that even- , tually the gear lever will no longer be a standard fitting. Instead, the eor- i rect ratios will be automatically selected, to the vast improvement of both performance and economy. In the meantime, efficient use can he made of the gear-box if the driver remembers always to change gear as soon as the road speed has dropped to a poont where either the engine seems to be labouring or is incapable of giving satisfactory acceleration. Attention to the latter factor will be found of great assistance in traffic driving, and will materially increase safety. . Six or eight cylinders are not neces- : sary to good performance, as many motorists heem to think. A good, modern four will do all thatj§. neces- : sary, and usually at a lower first and upkeep cost. It is often possible, however, to obtain a reasonably good performance in a six at a lower manufacturing cost than that of a ,four, particularly as regards smoothness of running.