Global Hybrid Cooperation

Global Hybrid Cooperation (formerly called Advanced Hybrid System 2 or AHS2) is a set of hybrid vehicle technologies jointly developed by General Motors, Daimler, and Chrysler LLC, with BMW joining in 2005. It uses 2 or 3 planetary gearsets in an automatic transmission: one on the internal combustion engine side (input split) paired with a second (output split), forming the compound split, and possibly one third additional planetary gearset to multiply the number of fixed gear ratios (up to 4). General Motors has stopped using the "AHS2" name as of 2006, preferring to call it simply a "two-mode hybrid system".

This technology was named as "Technology of the Year" for 2007 by Automobile Magazine.

While Toyota's Hybrid Synergy Drive may appear similar in that it also combines the power from an Internal combustion engine (ICE) and a pair of electric motor-generators; however in its current form, Toyota uses only one planetary gearset providing only single mode functionality (i.e. input split only) using a series/parallel architecture. While, Honda's Integrated Motor Assist uses a traditional ICE and transmission where the flywheel is replaced with an electric motor: it is a simple parallel architecture, requiring the addition of a mechanical continuously variable transmission. (i.e. not electrically variable)

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