Subaru is quietly laying the groundwork for a potential return of the WRX STI hatchback, a model enthusiasts have missed since its discontinuation in 2014. Rather than announcing a new road car outright, the company is testing a high-performance version of the hatchback on the racetrack – a strategic move that suggests a future production model isn’t off the table.
Development via Racing
The strongest indication comes in the form of the Subaru High Performance X Version II (HiPerfX2), designed to compete in the ST-Q class of Japan’s 2026 Super Taikyu Series. This follows a previous WRX-based sedan campaign, indicating Subaru is methodically developing its performance vehicles through real-world racing conditions. The HiPerfX2 debuted at the 2026 Tokyo Auto Salon, building on the earlier Performance-B STI Concept showcased at the Japan Mobility Show 2025.
Visually, the racecar is aggressive, with wide fender extensions, custom bumpers, a vented hood, and a large rear wing. It measures 4,514 mm (177.7 inches) in length – slightly longer than a standard Impreza – with a wheelbase matching the current WRX sedan. Subaru emphasizes that much of the hardware is pulled from existing parts, including the engine, suspension, brakes, and differential.
Engineering Approach
Team SDA Engineering started with a “body in white” rather than modifying a production model, streamlining the development process. Engineers from both automotive and aerospace industries collaborated on the aero components and underbody design, demonstrating a serious approach to performance optimization.
Performance Specs
The HiPerfX2 is powered by a motorsports-tuned 2.4-liter turbocharged boxer four-cylinder engine, producing 359 hp (268 kW / 364 PS) and 350 lb-ft (475 Nm) of torque. The car runs on carbon-neutral E20 fuel developed in partnership with ENEOS, and power is delivered to all four wheels via a six-speed manual transmission and a revised all-wheel-drive system. Initial track testing at Mobility Resort Motegi saw 54 laps completed without issue, confirming the platform’s stability.
Implications for Future Models
Subaru describes the racecar as a “development vehicle” intended to evolve further through motorsport. This is significant because the company is also phasing out orders for the current WRX sedan in Japan. If a new WRX STI does arrive around 2027, it’s likely to resemble the widebody hatchback currently being tested.
The HiPerfX2 project could be Subaru refining a mechanical package for a future road-going hot hatch, positioning it as a direct competitor to the Toyota GR Corolla and Honda Civic Type R. By rigorously testing the platform in the demanding Super Taikyu series, Subaru is strategically preparing for a high-performance revival that will appeal to enthusiasts.
