As oil reserves dwindle and environmental awareness increases, virtually all sectors of the auto industry are shifting their engine development programs to incorporate a wide variety of alternative fuels. Now, it appears Subaru are considering producing what could become a (gasp!) diesel WRX STI.

The performance car segment hasn’t been immune to this shift either, and Japanese manufacturers have been toying with alternative means of propulsion for quite some time. Toyota has the hybrid FT-HS concept car and Supra HV-R, while Honda have just confirmed their CR-Z hybrid hatchback will be entering production soon. Mazda have their hydrogen-powered RX-8 Hydrogen RE, while Honda and Mitsubishi are both testing the waters with the diesel-engined Civic Type R and Concept-RA.

According to Auto Express, the diesel WRX will be powered by the same 110kW flat-four diesel found in the Subaru Legacy, however an STI version could see output bumped up to 134kW

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 and 350Nm guise this September, however, a tuned version with 180bhp and 400Nm of torque could be used in a racy STI version.

We’re not sure what kind of performance advantage a diesel powerplant would give the STI, as the existing petrol-powered EJ20 already develops a peak torque figure of 422Nm, while power is much higher than the diesel at 227kW. Fuel economy aside, a diesel motor (at least, not any current Subaru diesel) makes little to no sense in Subaru’s sports flagship. In the plain ‘ol WRX maybe, but the STI? We think not.

[Source: Auto Express]
[Image courtesy of Subaru]