Subaru admits that its EJ25 engine utilised in the soon to be release Subaru WRX STI has all but reached its full potential.
Subaru WRX project manager Masuo Takatsu admitted that work on the engine for the new Subaru WRX STI was not high on the agenda, given more could be done with an improved chassis and body structure.
“[In regards to] the original EJ engine, we realised that we have sort of reached the peak and this is sort of the… we are not saying we have completed it, but it’s at the level that we can say that we have reached the highest point.” Takatsu told CarAdvice at the STI’s global launch in California last week.
The fourth-generation Subaru WRX STI still utilises the tried and tested 2.5-litre EJ engine with 227kW and 392Nm of torque (in American guise) which is up 6kW but actually down 14Nm compared to the Australian specification of the model it’s set to replace.
Unlike most sports car that get a generational upgrade, the all-new STI fails to deliver much in terms of an outright power and torque increase. A sore point for Subaru fans that were hoping for 250kW-plus power figures.
The argument has been to keep the same EJ engine as it’s motorsport-friendly in terms of durability and it’s modification-friendliness.
Nonetheless, the explanation and focusing of research and development budget appears to have gone into areas that needed it more.
“With the chassis and the previous body, we weren’t able to use the full potential of the engine, so we believe with the new STI we are enhancing the body structure and chassis to [properly] use the engine power.” Takatsu continued.
He admits that while there are currently no plans to change the power train from a turbocharged four-cylinder engine, to say a hybrid-assisted system or a twin-turbo setup, everything is on the table for future models.