Twin Clutch SST (Sport- or Sportronic Shift Transmission) is the brand name of a six-speed dual-clutch automatic transmission, developed by Getrag for Mitsubishi Motors.[1] The system was first incorporated in the 2008 Lancer Evolution X,[2][3] and was designed to be a more performance-oriented system than that developed by rival manufacturers,[4] with shorter gear ratios optimized for acceleration.[5]