Remember Subaru's Advanced Tourer concept from last year's Tokyo motor show? Believed to preview the next Liberty, the silver wagon was virtually ignored as the media pored over the BRZ coupe, co-developed with Toyota.



But it turns out the Advanced Tourer could actually point to the next Impreza, or more importantly, a fire-breathing WRX, according to new reports.



Due in 2015, the next-generation ''Rex'' and its sibling, the STI, are likely to get a harder edge following complaints that the current generation is too civilised and tame. The WRX and STI have become separate models in the Subaru range, no longer part of the normal Impreza model cycle.



Though details remain few, the rorty pair are believed to be powered by a 2.0-litre turbocharged horizontally opposed four-cylinder engine, possibly with direct injection - down from the current models' 2.5-litre unit - with power sent to all four wheels.



The STI will again deliver even more power, bigger brakes and even sharper handling to maintain its flagship status.



Despite the engine downsize, expect the WRX to muster more power and torque than the current car's 195kW/343Nm outputs while using significantly less fuel. Subaru is believed to have taken a patent on electrically powered turbo technology, which could eradicate complicated piping associated with turbocharging and create power more efficiently with less turbo lag.



The company also plans to roll out continuously variable transmissions across all its volume-selling models, and possibly even the WRX, for a claimed 20 per cent fuel saving over a conventional automatic.



While the car's interior is said to become more mature, the exterior will be more aggressive to suit the personality of the rally-ready racer. Overall, it will reportedly adopt the Advanced Tourer's angular styling.