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.HSD is a refinement of the original Toyota Hybrid System (THS) used in the 1997 to 2003 Toyota Prius. The second generation system THS II first appeared on the redesigned Prius in 2004. The name was changed in anticipation of its use in vehicles outside the Toyota brand (Lexus; the HSD-derived systems used in Lexus vehicles have been termed Lexus Hybrid Drive, although the Lexus implementation is really a variation of the THS III), the THS III was implemented in the 2006 Camry, and would eventually be implemented in the 2010 ""third generation"" Prius, and the 2012 Prius c. The THS III is designed for increased power and efficiency, and also improved ""scalability"" (adaptability to larger as well as smaller vehicles), wherein the ICE/MG1 and the MG2 have separate reduction paths, and are combined in a ""compound"" gear which is connected to the final reduction gear train and differential; it was introduced on all-wheel drive and rear-wheel drive Lexus models. By May 2007 Toyota had sold one million hybrids worldwide; two million by the end of August 2009; and passed the 5 million mark in March 2013. As of September 2014, more than 7 million Lexus and Toyota hybrids had been sold worldwide. The United States accounted for 38% of TMC global hybrid sales as of March 2013.