Toyota hybrid vehicles commonly use an e-CVT, or electronic continuously variable transmission.
Toyota’s Hybrid Synergy Drive does not work like a conventional stepped automatic transmission. Instead, it combines a gasoline engine, electric motor-generators, power electronics and a planetary gearset. Computer control continuously adjusts how engine and motor power reach the wheels, producing the smooth ratio changes associated with a CVT.
The “e” matters: Toyota’s system achieves its continuously variable behavior through an electromechanical power-split arrangement rather than a traditional belt-and-pulley CVT. One motor-generator helps control engine speed and can produce electricity, while another contributes driving torque.
Toyota’s first-generation hybrid system appeared in the Japanese-market Prius in 1997. The later Hybrid Synergy Drive name was used as the technology expanded to models such as the Camry, Highlander and Lexus hybrids. Drivers may feel engine speed rise without a conventional gearshift because the system is managing efficiency rather than selecting fixed gears.