Subaru Impreza

Subaru strikes oil with new Impreza STI diesel

Japanese firm is planning to unleash hot oil-burner.

Auto Express Car Reviews

22nd February 2008

Have you ever hankered after a Subaru Impreza STI, but been put off by its poor fuel economy?

Well, a fresh alternative could be on the way. Auto Express has learned Subaru is planning a hot diesel version of its rally-inspired 4WD hatch.

Power is set to come from the company’s all-new 2.0-litre flat-four cylinder boxer unit, which we tried for the first time in the Legacy Sport Tourer (Jan 2008). This will join the Impreza range in standard 148bhp guise this September. However, a tuned version with 180bhp could be used in a racy STI version.

Add a torque output of around 400Nm – up 50Nm on the petrol engine – and the high-performance model could sprint from 0-60mph in seven seconds and accelerate on to a top speed of 140mph. Yet the biggest benefit would be fuel economy of around 45mpg. As the boxer diesel is smaller than the STI’s petrol engine, it would be ideal for a performance model. The turbocharger is mounted beneath the engine, attached directly to the catalytic converters, to give a lower centre of gravity. The powerplant weighs no more than the current version, and would also help slash the STI’s emissions by nearly 40 per cent, from the petrol’s 243g/km to about 155g/km. That could reduce the Subaru’s road tax burden and attract fleet drivers when the car arrives next year.