According to Motoring's speculation, the next STI might use an electric motor at the back to power the rear axle and an upgraded version of the FA20 turbocharged 2.0-liter at the front. A new dual-clutch six-speed gearbox would help the power get to the road, and the total system could allegedly offer around 322 horsepower versus 305 hp from the current US model.
This rumor also claims the next-gen STI would continue as a sedan when it arrives in 2017. Like previous iterations, the four-door will share underpinnings with the Impreza, which will mean a move to Subaru's new modular platform. The standard hybrid might only be the beginning of electrification for the future STI. Motoring's source also claims the company has a plug-in hybrid variant under development, but it might not debut until the 2018 Tokyo Motor Show.
A hybrid STI could be exciting, but until there are solid facts, this rumor joins a long history of powertrain speculation about the high-performance Subaru. In 2008 and 2010, reports emerged about a diesel version, but it never appeared. We once even heard that the current-gen WRX might boast an electric turbo.