New Subaru WRX STI: Performance and Engine Specs

While the regular Subaru Impreza and other members of the Subie lineup switched to the new Subaru Global Platform four years ago, the higher-performance WRX and WRX STI versions of the Impreza have yet to follow suit. They remain based on the previous-generation Impreza models. According to a report from Forbes, however, that might finally be changing with a new engine that is being developed for the next STI, promising to deliver 400 horsepower and 361 lb-ft of torque.

Engine Specs and Performance Upgrades

Citing sources close to Subaru, Forbes reveals that the next WRX STI is expected to launch in 2021 and will feature an “all-new” turbocharged 2.4-liter boxer four-cylinder engine. Subaru already incorporates a 2.4 turbo engine, the FA24, in the Ascent three-row SUV and XT variants of the Legacy and Outback. Consequently, it seems likely that the STI will receive a significantly upgraded version of this engine. Currently, the FA24 produces 260 hp and 277 lb-ft, which means considerable enhancements are needed to achieve that ambitious 400-hp target.

Current WRX STI Setup

The existing WRX STI utilizes the well-known EJ25 turbocharged 2.5-liter engine, generating 310 hp and 290 lb-ft in standard configuration. Meanwhile, the limited-production S209 variant boosts that output to 341 hp and 330 lb-ft. While this is an impressive achievement, it highlights the limitations of the aging engine architecture, first introduced in the mid-’90s. It remains uncertain what will power the new base WRX, which currently utilizes a turbocharged 2.0-liter FA-series engine offering 268 horsepower.

Upgraded Features for the New STI

The new STI-specific FA24 will reportedly feature a reinforced crankshaft, beefier pistons, and increased boost pressure. Subaru engineers are taking inspiration from the 2.0-liter turbo engine available in the Mercedes-AMG A 45, CLA 45, and new GLA 45, which generates an impressive output of 415 horsepower and 368 lb-ft of torque in “S” guise. Additionally, the next-gen STI is expected to be equipped with Subaru’s full-time symmetrical all-wheel drive system and enhanced braking capabilities, ensuring a thrilling driving experience.

Stylish Design Expectations

For styling, anticipation surrounds the next-gen WRX and STI to draw from the recent Viziv Performance and Viziv Performance STI concepts. However, similar to most of Subaru’s recent products, it’s expected that the final design for the production WRX will be somewhat toned down compared to the aggressive looks of the concepts that inspire it. Exact timing for the launch remains unclear, but forecasts suggest that the STI would debut first in 2021, with the standard WRX following later.