We believe the main reason is to create differentiation between the two models so that the WRX and STI variants can earn their status as unique sport models and not just halo models for the Impreza.
The other reason is the new 2.0-litre boxer engine (pictured above), which Subaru currently has no plans to turbocharge. This means the EJ25 turbocharged engine (pictured below) currently in the WRX, STI, Forester XT/S-Edition and Liberty, is going to last a while longer before a replacement is found. The EJ design architecture is now over 20 years old but has been extensively modernised over the years and can still keep up and even outdo its competitors.
Speaking to CarAdvice in New York, Subaru's Impreza Product General Manager, Mr Akihide Takeuchi, said work on the replacement turbocharged engine has commenced but would not give any further details. He did confirm that it will not be based on the EJ25 and will not simply be a turbocharged version of the new boxer engine.
He said that the new boxer engine was designed with fuel efficiency and performance in naturally-aspirated application as top priority, making its design architecture less suitable for a turbocharger.
Mr Takeuchi said that a decision on the future platform of the WRX and STI was due very soon. Talk of separation between the Impreza and its sport derivatives makes us wonder if we might see a two-door WRX/STI model in the future.
On the surface this may sound like bad news for WRX/STI fans but it can indeed mean that future models will be built from the ground up to be sports cars as oppose to just being an Impreza with performance bits.
In related news, talk of a hybrid Impreza is still on-going with Mr Takeuchi admitting that "hybrid is very important" as his company continues to study the technology for viability.
Perhaps the next generation Impreza WRX/STI models will be turbocharged hybrids? Only time will tell. Let us know if you'd love to own a two-door WRX/STI!