The number of transmission speeds in new light-duty vehicles has been growing over the last few decades. By 2018, 96% of cars and 95% of light trucks were at least six speeds, according to the US Department of Energy (DOE).

The share of light truck transmissions in the 9+ category grew to 22% in 2018. Continuously variable transmissions (CVTs) were almost one-third of car production and 13% of light truck production. A greater number of gears improves fuel economy and performance by more closely matching the wheel speed to the optimum engine speed.

Source: DOE