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. 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.
Note: Data are production-weighted averages for each model year. Data for model year 2018 are preliminary. CVT data include both hybrid and non-hybrid. Data for cars include some 2-wheel drive sport utility vehicles (SUVs). Data include light trucks less than 8,500 lb. Beginning with 2011, SUVs and passenger vans up to 10,000 lb were also included. See source for details.
Source:
U.S. Environmental Protection Agency, Light-Duty Automotive Technology, Carbon Dioxide Emissions, and Fuel Economy Trends: 1975 Through 2018, March 2019, and personal communication with the EPA Office of Transportation and Air Quality.