STI stands for Subaru Tecnica International. It is Subaru’s motorsport and performance company, established on April 2, 1988. STI develops competition cars, complete high-performance road cars, chassis and engine components, performance parts, and limited-production models.
On a Subaru, however, the STI name appears in several contexts. A WRX STI is a complete high-performance model with major mechanical changes. STI also develops optional parts for regular Subaru models, including WRX spoilers, exhausts, wheels, and suspension components. A model labeled tS means “Tuned by STI,” which can include meaningful chassis upgrades without making it a WRX STI.
WRX and STI are separate names. WRX stands for World Rally Experimental, while STI identifies the organization and its work described here.
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What is Subaru Tecnica International?
Subaru Tecnica International Inc. is the company responsible for Subaru’s motorsport programs and many of its highest-performance vehicles and parts. Subaru created STI in 1988 as a subsidiary of Fuji Heavy Industries, the company now named Subaru Corporation.
STI’s official business activities include:
- Managing Subaru motorsport programs.
- Developing competition engines and chassis.
- Planning and developing STI versions of Subaru vehicles.
- Creating limited-production STI cars.
- Developing motorsport and street-performance parts.
That makes STI more than the name of a WRX trim. It is an engineering and motorsport organization whose name also appears on complete cars, tuned models, replacement parts, accessories, and merchandise.
What does an STI badge mean?
The meaning depends on where the badge appears.
| STI designation | What it identifies | Is it a full WRX STI? |
|---|---|---|
| WRX STI | A factory high-performance WRX model with STI-specific drivetrain and chassis hardware | Yes |
| STI complete car | A limited-production vehicle developed and sold as a complete STI model, such as the S-series cars | Not necessarily named WRX STI |
| tS | “Tuned by STI,” usually emphasizing chassis, brakes, suspension, and interior changes | No |
| STI Sport | A market-specific performance or appearance grade with STI involvement | No |
| STI performance part | An individual accessory or component, such as an exhaust, spoiler, wheel, or suspension part | No |
This distinction matters when identifying a used car. An STI badge, shift knob, wing, or exhaust can be installed on another Subaru. The VIN, model documentation, drivetrain, brakes, and other factory equipment identify an original WRX STI.
Is a WRX STI just a higher WRX trim?
In a dealership lineup, the STI sat above the regular WRX. Mechanically, it was more extensive than a typical appearance or convenience trim.
Modern U.S.-market WRX STI models used a different engine from the contemporary WRX, an STI six-speed manual transmission, Driver Controlled Center Differential, performance-oriented front and rear differentials, larger Brembo brakes, and STI-specific suspension and steering hardware. The exact equipment changed by generation and model year.
Our WRX vs. STI comparison covers the horsepower, engines, transmissions, AWD systems, brakes, fuel economy, and model-year differences in detail.
A short history of STI
STI’s history began before the WRX STI reached the United States.
- 1988: Subaru Tecnica International was established.
- 1989: A Subaru Legacy prepared for a high-speed endurance attempt set an FIA-recognized 100,000-kilometer record.
- 1990: STI began Subaru’s full-scale World Rally Championship program at the Safari Rally.
- 1994: Subaru offered the first Impreza STI versions in Japan.
- 1995-1997: Subaru won three consecutive World Rally Championship manufacturers’ titles.
- 1998: STI released the limited-production Impreza 22B STI.
- 2004: The WRX STI reached the U.S. market with a 300-horsepower EJ257, six-speed manual, DCCD, and Brembo brakes.
- 2008: Subaru withdrew its factory team from the WRC after the season, but STI continued developing road cars, parts, and cars for other racing programs.
STI has since used S-series names including S201, S209, and S210 for limited complete cars. It has also applied its chassis work to the WRX, BRZ, Legacy, Forester, Levorg, and other Subaru models through tS, STI Sport, and market-specific packages.
Does STI still exist?
Yes. The absence of a current U.S.-market WRX STI does not mean Subaru Tecnica International closed.
STI continues to develop motorsport vehicles, complete cars, and performance parts. In 2025, it released the 500-unit S210 complete car in Japan, based on the WRX S4 STI Sport R EX. Subaru also sells the current U.S.-market WRX tS with electronically adjustable dampers tuned by STI, Brembo brakes, and other chassis upgrades.
The WRX tS is not a replacement badge for the discontinued U.S.-market WRX STI. It uses STI-developed chassis tuning, but it does not have the former STI’s close-ratio six-speed transmission, DCCD, differential package, or EJ257 engine.
STI, STi, and tS capitalization
Subaru’s current company name and branding use STI in capital letters. Older cars, brochures, and enthusiast writing often use STi. Both refer to Subaru Tecnica International.
The tS badge is a different designation. It means “Tuned by STI.” The lowercase “t” and uppercase “S” distinguish an STI-tuned version from a complete STI model.
Sources
- About Subaru Tecnica International - company name, establishment date, business activities, motorsport history, and vehicle milestones.
- STI road-car history - STI complete cars, tS models, STI Sport models, and S-series chronology.
- STI Legacy tS history - Subaru’s explanation of the tS designation and chassis-tuning focus.
- STI S210 history - the WRX S4-based, 500-unit S210 complete car.
- Subaru WRX tS features - current U.S. STI-tuned suspension and WRX tS equipment.
- Subaru 2021 WRX and WRX STI brochure - final U.S.-market WRX STI equipment and model comparison.
- Subaru WRX STI Type S front photo - photo by Tokumeigakarinoaoshima, released under CC0.
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