Hybrid Synergy Drive

Hybrid Synergy Drive (HSD) is the brand name of Toyota for hybrid car drive train technology. It is used in its Yaris, Auris, Prius, Highlander Hybrid, Camry Hybrid, Estima, Alphard, Lexus RX 400h/RX 450h, Lexus ES 300h, Lexus GS 450h, Lexus LS 600h/LS 600hL, Lexus CT 200h, Lexus IS 300h, Lexus HS 250h and Lexus NX 300h automobiles. Toyota also licenses its HSD technology to Nissan for use in its Nissan Altima Hybrid. Its parts supplier Aisin Seiki Co. offers similar hybrid transmissions to other car companies.

HSD technology produces a full hybrid vehicle which allows the car to run on the electric motor only, as opposed to most other brand hybrids which cannot and are considered mild hybrids. The HSD also combines an electric drive and a planetary gearset which performs similarly to a continuously variable transmission. The Synergy Drive is a drive-by-wire system with no direct mechanical connection between the engine and the engine controls: both the gas pedal/accelerator and the gearshift lever in an HSD car merely send electrical signals to a control computer.