Subaru Trademarks ACX STI: Is an Electric Sports Coupe Coming?

Subaru may be developing a new sports car, potentially with an STI variant. Recent trademark filings for ACX and ACX STI suggest an electric vehicle (EV), while rumors indicate a combustion-powered sports car could be based on the Toyota GR Celica.

The performance division of Subaru has been a hot topic among enthusiasts. Fans of Subaru Tecnica International (STI) have been eagerly awaiting the return of the WRX STI hot hatch, but new reports suggest the company might also be working on a sports coupe with a dedicated STI version.

The Trademark Filings

According to CarSales, Subaru has trademarked the ACX and ACX STI names with IP Australia. This is a nod to the ACX-II concept car from 1985. The Australian outlet suggests a gasoline-powered application, citing separate filings for “Flat Shift” and “Rev Sync” as supporting evidence. However, trademarks filed in other regions tell a different story.

In the US, Canada, and the UK, Subaru has trademarked the names ACX, VPX, and ZPX, along with their STI variants. Each filing includes a specific description: “Automobiles and structural parts therefore electric cars.” This wording strongly indicates an electric powertrain.

Of the three names, only VPX has been paired with a Wilderness designation, hinting at a taller, more utilitarian vehicle—possibly a truck, crossover, or SUV. The context for ACX and ZPX remains unclear, leaving earlier rumors and reports as the primary sources of speculation. One possibility is that either name could belong to the long-rumored successor to the BRZ.

Design Speculation

Independent digital artist Theophilus Chin has envisioned the BRZ successor as a fully electric sports car. His design draws from the Performance-E STI Concept, featuring a modernized two-door silhouette that retains the BRZ’s recognizable proportions.

What About Internal Combustion Engines (ICE)?

While the ACX trademark filings strongly suggest an electric powertrain, the ongoing partnership between Subaru and Toyota opens the door for a combustion-powered sports car to coexist with it.

Subaru recently debuted a widebody BRZ-based rally car, the Boxer Rally Spec.Z, powered by a turbocharged engine and all-wheel drive. This vehicle is built to compete in the Japan Rally Championship (JRC). Meanwhile, Toyota is testing an unidentified World Rally Championship (WRC) contender with a two-door coupe profile, widely believed to be the competition version of the upcoming GR Celica.

While the two rally cars share no mechanical components, there is still a potential path for Subaru to develop a road-going sibling to the production Toyota GR Celica when it arrives. It remains uncertain whether Toyota will opt for a front-engined or mid-engined layout for the road car.

Toyota has confirmed that a next-generation GR 86 is in development, but Subaru’s side of the partnership may take a different direction. The next BRZ could go fully electric and adopt the elevated stance previewed by the Sport Mobility Concept.