Most now-made passenger cars with gasoline or diesel engines use transmissions with four–ten forward equipment ratios (also known as speeds) and just one reverse equipment ratio. Electric powered motor vehicles usually use a set-gear or two-velocity transmission without any reverse gear ratio. As technologies advanced, the synchromesh gearbox was released. https://automobile-gearbox63849.bloggactif.com/34978567/new-step-by-step-map-for-automobile-gearbox