It is advisable to use several gear ratios.
In order to take full advantage of the engine power and to better adapt the car to different driving resistances, several gear ratios are used between the engine and the tires on the vehicle.. Gearboxes (gear) most of the time they have cars 3-, 4- or 5-speed forward gear and one gear in reverse. In the gearbox, at least two pairs of wheels are involved in each gear ratio.