Sources close to Subaru are indicating the next WRX STI could adopt a hybrid powertrain once it will be out sometime in 2017.
Recent spy shots and a concept have shown Subaru is just about ready to take the wraps off the new Impreza and most likely WRX STI development is well underway. The cars are set to ride on the new Subaru Global Platform (SGP), but the WRX STI is expected to adopt a hybrid arrangement to boost power and efficiency at the same time. It will use an evolution of the 2.0-liter turbo boxer engine that will work closely with an electric motor.
Interestingly, the next WRX STI could feature a newly developed all-wheel drive system as word on the street says the rear axle will be electrically-driven. That means the combustion engine will power the front wheels whereas the electric motor will propel the rear axle. Adding an electric motor and all the other necessary hardware will surely increase weight, but this will be offset by the SGP likely bringing a significant diet.
A combined output of more than 326 PS (240 kW) is expected, along with a new six-speed automatic manual dual-clutch gearbox. This hardware arrangement will apparently enable the high-performance sedan to consume less than 6.5 liters / 100 km (36.2 mpg US or 43.4 mpg UK) in the combined cycle.
The WRX STI will probably see the light of production day sometime in 2017 and could be joined about a year later by a plug-in hybrid variant.
Note: 2015 Subaru Impreza Sedan Concept pictured.