Subaru Tecnica International (STI), the performance division of Subaru, has unleashed a beast exclusively for American roads: the STI S209. This limited-edition marvel marks the very first S-line STI vehicle meticulously engineered and produced specifically for the United States. Elevating the iconic WRX STI to unprecedented levels, the S209 is not merely an upgrade; it’s a complete transformation encompassing enhanced power, razor-sharp handling, aggressive aerodynamics, and an unparalleled driver-focused experience. Born from STI’s relentless pursuit of performance, the S209 undergoes final assembly in Kiryu, Japan, where master technicians apply engine enhancements and bodywork modifications. This meticulous process necessitates STI to homologate the S209 for US standards, solidifying its status as the first truly “STI-built” Subaru ever offered in the American market.
Alt text: Front three-quarter view of a Subaru STI S209 in WR Blue Pearl showcasing its aggressive wide-body stance and front fender vents.
The S209 proudly carries the torch of STI’s high-performance lineage, a tradition steeped in exclusive Japanese Domestic Market (JDM) models ranging from the S201 in 2000 to the S208 in 2018. However, the S209 transcends its predecessors, drawing direct inspiration and technological prowess from STI’s most formidable track weapon: the WRX STI Nürburgring Challenge racecar. This very racecar conquered the SP3T class at the grueling 2019 24 Hours of Nürburgring, marking STI’s sixth triumph in this demanding endurance race. The spirit of Nürburgring, the ultimate proving ground, is deeply embedded within the DNA of the Subaru S209.
Echoing its Nürburgring conqueror sibling, the S209 boasts a dramatically widened stance courtesy of an expanded wide-body exterior. This aggressive treatment extends the car’s overall width to an imposing 72.4 inches, a full 1.7 inches broader than a standard WRX STI. These muscular, bulging fenders are not just for show; they purposefully accommodate wider front and rear tracks, increased by 0.6 inches both front and rear, and house bespoke 265/35 Dunlop® SP Sport Maxx® GT600A summer-only tires. These high-performance tires are specially developed by Dunlop exclusively for the S209 and are expertly wrapped around lightweight 19 x 9-inch forged BBS alloy wheels. This tire and wheel combination is a crucial component in achieving the car’s astounding maximum lateral grip, exceeding 1.0 g, delivering phenomenal cornering capabilities.
Alt text: Close-up of the Subaru STI S209’s lightweight forged BBS wheel and Dunlop SP Sport Maxx GT600A tire, highlighting the performance-focused wheel and tire combination.
Further emphasizing its performance-oriented design, the S209 features functional vents integrated into the front fenders. These vents are strategically placed to enhance engine cooling, ensuring optimal thermal management even under demanding driving conditions. Similarly, vents on the rear fenders are designed to manage airflow, rectifying air turbulence to minimize drag and maximize downforce, contributing to the vehicle’s stability at high speeds and in corners. To match the enhanced performance, the S209 is equipped with Brembo brakes, featuring cross-drilled steel rotors and robust 6-piston monoblock front calipers paired with 2-piston monoblock rear calipers. These high-performance brakes are further enhanced with upgraded high-friction pads, providing exceptional stopping power and improved fade resistance, crucial for both track days and spirited driving.
Beneath the S209’s widened and sculpted body lies a meticulously engineered chassis designed for unparalleled handling. Specially developed Bilstein® dampers are at the heart of the suspension system, working in concert with stiffened coil springs, a 20mm rear stabilizer bar, and pillow-type bushings for both the front and rear lateral links. These components work in harmony to provide precise control and feedback. Reinforcements to the front crossmember and rear subframes further enhance chassis rigidity, mirroring the approach taken in the Nürburgring racecar. Adding another layer of sophistication, the S209 incorporates a flexible front-strut tower bar and flexible front/rear draw stiffeners, technology derived directly from the race track.
Alt text: A detailed view of the Subaru STI S209’s Bilstein dampers and suspension components, emphasizing the performance-tuned chassis.
Unlike a conventional rigid strut tower bar, the flexible bar is split and joined with a pillow ball joint at its center. This innovative design allows for longitudinal movement while maintaining lateral stiffness. The result is optimized tire grip during aggressive cornering while preserving a degree of ride compliance in straight-line driving. Complementing the flexible strut tower bar, the draw stiffeners apply tension between the body and cross member, precisely managing chassis flex. This sophisticated approach enhances stability during cornering and contributes to improved ride quality, handling responsiveness, and steering precision. Further track-derived aerodynamic enhancements include front, rear, and side under spoilers, aggressively styled front bumper canards, and a lightweight carbon-fiber roof panel and rear wing, all contributing to the S209’s exceptional performance envelope.
Powering the Subaru S209 is a thoroughly reworked iteration of the legendary EJ25 2.5-liter turbocharged BOXER engine. Featuring an STI turbocharger manufactured by HKS®, this enhanced engine delivers a potent 341 horsepower at 6,400 rpm. This impressive power output is achieved through the use of a larger turbine and compressor (increased by 6 and 8 percent, respectively, compared to the standard WRX STI) and a significant increase in maximum boost pressure, now reaching 18.9 psi (up from 16.2 psi in the WRX STI). Each S209 engine proudly displays a unique serial number plate, signifying its bespoke nature. Beyond peak horsepower, the enhanced BOXER engine also boasts a substantial increase in midrange torque, producing 330 lb.-ft. at 3,600 rpm. This surge in torque translates to quicker corner exits and enhanced responsiveness on and off the track.
Alt text: Under-hood view of the Subaru STI S209’s engine bay, highlighting the EJ25 turbocharged BOXER engine and STI performance components.
Exclusively designed for ultimate driver engagement, the S209 is equipped with a close-ratio 6-speed manual transmission. This transmission channels power to Subaru’s renowned Symmetrical All-Wheel Drive system, complete with front and rear limited-slip differentials, a Driver Controlled Center Differential (DCCD), Active Torque Vectoring, and Multi-Mode Vehicle Dynamics Control. The S209’s SI-Drive system has been recalibrated and offers three distinct modes: Intelligent (I) for optimized fuel efficiency and smooth power delivery, Sport (S) for a balanced blend of responsiveness and control, and Sport Sharp (S#) for maximum acceleration performance. STI engineers specifically recommend Sport mode for circuit driving, as its less aggressive throttle mapping allows for finer driver control and precision.
To ensure the EJ25 engine receives ample airflow, the S209 employs a high-flow intake system. This system incorporates a newly designed intake duct, an induction box with a conical air filter, a silicone turbo inlet duct, and a nostalgic nod to the 2004-07 WRX STI – an intercooler water spray system. This manually operated system, activated via steering-wheel paddles, lowers intercooler temperatures, further enhancing performance. To match the increased airflow, the S209 also features a high-flow fuel pump, larger fuel injectors, and an STI-tuned engine control module. High-performance mufflers reduce airflow resistance by 17 percent, while larger, hand-polished stainless-steel exhaust tips, measuring 101mm in diameter, deliver both an aggressive aesthetic and a thrilling exhaust note.
The S209 distinguishes itself from other STI models through a series of exclusive interior and exterior enhancements. An STI badge replaces the traditional Subaru star cluster on the center of the D-shaped steering wheel, which is wrapped in Ultrasuede® with elegant silver stitching, a treatment that extends to the lid of the center console storage box. A unique S209 serial number badge is prominently displayed on the center console, while S209 badges further adorn the passenger-side dash and the headrests of the Recaro® front bucket seats, which feature distinctive silver-hued inserts. Externally, special S209 badges are affixed to the front grille, fenders, and rear decklid, leaving no doubt about the car’s exclusive nature.
Alt text: Interior view of the Subaru STI S209 showcasing the Recaro seats, Ultrasuede steering wheel, and S209 badging, emphasizing the bespoke interior details.
With production limited to a mere 209 units, the STI S209 is an exceptionally rare and highly sought-after machine, exclusively destined for the US market. Available in striking WR Blue Pearl with gray BBS wheels or Crystal White Pearl with gold BBS wheels, the Subaru S209 represents the pinnacle of STI engineering and performance for American driving enthusiasts. While pricing details were announced closer to its late 2019 on-sale date, the S209 was undoubtedly positioned as a premium, collector-grade performance vehicle, cementing its legacy as the ultimate STI for the US market.
