Subaru Forester STI SG9
The Subaru Forester STI, designated SG9, was a Japan-market exclusive that answered a question many enthusiasts hadn't thought to ask: what happens when you put a WRX STI drivetrain in a practical family crossover? The answer, as it turned out, was one of the most entertaining and versatile vehicles of its era.
The Forester STI received the EJ255 turbocharged flat-four engine producing 265 horsepower — slightly less than the contemporary Impreza STI but more than sufficient for a vehicle of the Forester's size and weight. The turbo EJ255 provided excellent mid-range torque, ideally suited to the Forester's slightly taller gearing and higher center of gravity. The 5-speed manual transmission was the sole option, connected to Subaru's symmetrical AWD system with a driver-controlled center differential.
STI's involvement extended far beyond the engine swap. The suspension was completely reworked with inverted front struts (a signature STI feature), retuned springs and dampers, and revised geometry to account for the Forester's higher ride height and different weight distribution. Brembo brakes — 4-piston front, 2-piston rear — provided the kind of stopping power usually reserved for dedicated sports cars.
The exterior was distinguished from the standard Forester XT by a prominent STI rear wing, revised front bumper with larger air intakes, side skirts, and the iconic STI cherry red Brembo calipers visible through the alloy wheels. The overall effect was purposeful without being aggressive — the Forester STI looked like what it was: a practical vehicle with serious performance credentials.
Inside, the Forester STI received STI-branded seats with enhanced bolstering, an STI steering wheel, aluminum pedals, and boost and oil pressure gauges. The driving position was higher than the Impreza, providing excellent visibility while still feeling connected to the car's dynamics.
The Forester STI was remarkably effective as a performance vehicle. While it couldn't match the Impreza STI's outright pace due to its additional height and weight, it was surprisingly close — and its superior ride height and cargo capacity made it far more practical as a daily driver. The combination of STI performance, Forester practicality, and all-weather AWD capability created a vehicle that could drive to the ski slope, tackle the access road, and still provide engaging driving on the mountain passes.
The Forester STI SG9 is now recognized as a precursor to the performance SUV/crossover category that would explode in popularity over the following decade. It demonstrated that enthusiast-grade performance and everyday practicality were not mutually exclusive — a lesson the rest of the industry would take years to learn.
As a Japan-market exclusive, all Forester STI SG9s will be imports. Verify the STI specification through the chassis plate and confirm the presence of genuine STI components (Brembo brakes, inverted struts, STI ECU). The EJ255 engine is generally reliable but shares the EJ-series susceptibility to head gasket weeping and turbo bearing wear. Check for rust in the usual Subaru locations: sills, rear wheel arches, and subframe mounting points. The higher ride height means the suspension components are under different stress than the Impreza — check the strut top mounts and rear trailing arm bushings. Many examples will have been used as practical daily drivers, so interior wear may be more pronounced than a comparable-mileage Impreza STI.
Built at Subaru's Gunma Manufacturing Division on the SG Forester platform. The STI variant was exclusive to the Japanese domestic market and was never officially exported. Production ran from 2004 to 2008 across the second-generation Forester's lifecycle. The EJ255 engine was the same basic unit used in the US-market Forester XT and Legacy GT, but with STI-specific tuning and supporting modifications.