why5-speed instead of 7

[is64fun]

well i thought a lot but could not come up with an apropriate idea why mercedes used automatic transmission in slr. moreover, why did they used 5-speed isntead of 7-speed which is newer technology? any idea

and the second question: the f1 transmission in ferraris, do they faster than the manuel gearboxes like carrera gt or the smg2 in bmw? and is selespeed different form those???

[Ford Capri 2.8i]

Lets try giving a little expanation under my car knowledge....firstly, the merc AMGs policy has been always to launch very powerful cars on straight line based on big amount of torque (from low revs as a result), and accompanied by authomatic gearboxes....it seems that the sales go well and customers are quite happy with the authomatic gearboxes since the AMG versions are using the authomatic gearboxes in it models since quite a long time ago and their policy hasnt changed yet

about the transmission systems, as far as i know every sporty brand and model except mercedes are using some transmission system based on the semiautomatic gearbox system such as porsche and VW group( the DSG and the tiptronic), the BMW (the SMG), and FIAT group (the selespeed), where this system allows some quicker gear changes than the automatic gearbox system, its lighter and, and the cars fuel consumption is less than in the automatic gearboxes...whereas the merc uses the automatic system for its cars since its softer than the semiautomatic.......the fact that every AMG has 5 gearbox instead of 7?....probably due to some technical or reliability problems..you have to think that the merc engines are based on big torques and think that the big torques are the biggest enemies of the gearbox toward its reliability....anyway..merc announced a few months ago that from some day every automatic merc will get a 7 speed gearbox

finally......till the launch of the ferrari 430 and the new M5(both versions have improved their respective semiautomatic gearboxes) the VW Group DSG was the quickest one....from now on....ive no clue if BMW and ferrari has discovered a quicker gearbox than the DSG