Subaru WRX STI VA (2015-2021) Wheel Fitment Guide
The 2015-2021 Subaru WRX STI VA chassis is the fourth and final generation of the STI sold in the US — a seven-year run that ended after the 2021 model year when Subaru retired both the model and the EJ257 engine in the United States. Across the full generation, every USDM STI uses identical wheel hardware: 5×114.3 bolt pattern, 56.1mm center bore, and M12×1.25 lug nuts with 60° conical seats. The platform is one of the most well-documented aftermarket wheel platforms in the enthusiast world, with the 18×9.5 +38 setup serving as the de facto standard for flush stance.
Two important year-era differences affect wheel selection. First, the standard STI received a brake upgrade for the 2018 mid-cycle refresh: 2015-2017 STIs use 4-piston front Brembo calipers with 326mm front rotors, while 2018-2021 STIs use 6-piston front Brembo calipers with 340mm front rotors. The 6-pot calipers do not clear OEM 17″ wheels, but all VA STI configurations across both eras run 18″ minimum and clear OEM. Second, the VA generation produced two USDM-specific limited variants with unique OEM wheel hardware: the 2018 Type RA (500 units, 19×8.5 +55 BBS forged) and the 2019 S209 (209 units, 19×9 +48 BBS forged with widened body).
This guide covers the standard STI across the full 2015-2021 production run, plus standalone OEM cards for the Type RA and S209 limited variants. All aftermarket fitment data applies to all VA STI variants regardless of year.
About this guide: The fitment data below is compiled from owner-submitted builds and enthusiast forum research across NASIOC and the IWSTI (Iwsti) forum. We summarize what VA STI owners have reported running successfully so you have a researched starting point for your build.
Every FMB build goes through a sanity check and an engineering verification before forging. We cross-reference the configuration you're ordering against your trim and brake package and what's commonly documented on similar builds — and our manufacturing partner verifies the wheel itself (backspace, brake caliper clearance, structural spec) before production begins.
Fitment decisions involving ride height, tire choice, and suspension setup are yours and your installer's call. Use this guide as research, not as a substitute for a real fitment conversation.
Factory Wheel & Tire Configurations
The VA STI ran two standard wheel configurations across its production: the 2015-2017 standard wheel and the 2018-2021 refreshed wheel — both 18×8.5 ET55 forged or cast aluminum, both clearing the era-appropriate Brembo brakes. The Limited trim added an optional 19×8.5 ET55 wheel for 2018-2021 cars. Two USDM-specific limited variants in the same generation produced unique OEM wheels: the 2018 Type RA on 19×8.5 ET55 BBS forged, and the 2019 S209 on 19×9 ET48 BBS forged. All five OEM configurations share the same 5×114.3 bolt pattern, 56.1mm center bore, and M12×1.25 hardware.
Aftermarket Wheel & Tire Configurations
The VA STI is one of the most-documented aftermarket wheel platforms in the enthusiast world. Across the seven-year generation, the 18×9.5 +38 setup has emerged as the de facto standard flush configuration — paired with 245/40R18 or 255/35R18 tires, it works at stock or moderately lowered ride height on the vast majority of builds without fender modification. Owners pursuing more aggressive stance go to lower offsets (+22 to +35) with wider tires (265/35R18) and may need to roll rear fenders. All flush and aggressive configurations below clear the 6-piston front Brembo on 2018-2021 STIs and the 4-piston front Brembo on 2015-2017 STIs at 18″ diameter minimum. Hub-centric rings (56.1mm vehicle / 73.1mm typical aftermarket wheel) are required when installing aftermarket wheels with larger center bores than the OEM 56.1mm hub.
Three constraints define the VA STI fitment universe. First, brake clearance differs by year-era: 2015-2017 STIs use 4-piston 326mm front Brembo calipers, while 2018-2021 STIs use 6-piston 340mm front Brembo calipers. Both clear 18" wheels with appropriate spoke geometry, but the 6-pot Brembos do not clear OEM 17" wheels. Second, the 56.1mm OEM hub is small relative to most aftermarket center bore standards (typically 73.1mm) — hub-centric rings are required for any aftermarket wheel with a larger center bore. Third, the AWD drivetrain requires consistent rolling circumference across all four corners; running mismatched tire diameters or significantly different wear levels stresses the center differential. Always run identical tires across all four wheels and replace as a complete set.
Flush Fitment
Square Setup
Aggressive Fitment
Square Setup
What Happens When You Build With FMB?
The configurations above are a starting point — not a final spec. When you start your build, here’s what actually happens before anything is forged:
- FMB build review. We cross-reference the configuration you’re ordering against your trim and brake package, and compare it to what’s commonly documented on similar builds. If the setup you want falls outside what we’ve seen work on this platform, we’ll flag it before you commit.
- Manufacturer wheel verification. Our manufacturing partner verifies the wheel itself — backspace, brake caliper clearance for your brake package, and structural spec — before production begins.
- Design render approval. You see the final design and confirmed specs before any aluminum is touched.
Ride height, tire choice, alignment, and suspension setup are variables your installer handles on the car — not things we verify from our end. That’s why we ask for the vehicle details we do on the build form: they’re the inputs we can actually check against.
FAQ - Frequently Asked Questions
Standard delivery on the STI Base and Premium across the full 2015-2021 generation: 18×8.5 ET55 cast aluminum (Enkei) with 245/40R18 tires, square setup. The STI Limited received the optional BBS forged 18×8.5 ET55 wheel from 2015-2017, then transitioned to a 19×8.5 ET55 cast wheel with 245/35R19 tires from 2018-2021 alongside the 6-piston front Brembo upgrade. Two USDM-specific limited variants in the same generation produced unique OEM wheels: the 2018 Type RA (BBS forged 19×8.5 ET55, 500 units, gold finish) and the 2019 S209 (BBS forged 19×9 ET48, 209 units, in dark gray or gold). All OEM wheels share the 5×114.3 bolt pattern, 56.1mm center bore, and M12×1.25 lug nut hardware.
Yes — the 2018 mid-cycle refresh upgraded the standard STI brakes from 4-piston front Brembo with 326mm rotors to 6-piston front Brembo with 340mm rotors. Rear brakes also grew from 316mm to 326mm rotors. The yellow caliper finish on 2018-2021 STIs replaces the gold finish on 2015-2017 STIs. The S209 (2019 only) uses a unique silver-painted 6-piston front Brembo with drilled rotors and STI performance pads. All VA STI configurations across both eras run 18″ wheel minimum and clear OEM. The 6-piston Brembos do not clear OEM 17″ wheels — relevant only if you’re attempting to fit a smaller wheel for winter or track use.
5×114.3 bolt pattern, 56.1mm center bore, M12×1.25 thread pitch lug nuts with 60° conical seats and 19mm hex. Torque spec is 89 lb-ft (120 Nm). The 56.1mm OEM center bore is small relative to most aftermarket wheel center bore standards (typically 73.1mm) — hub-centric rings (56.1mm vehicle / 73.1mm wheel) are required when installing aftermarket wheels with larger center bores, otherwise vibrations at highway speeds will result. Subaru OEM lug nuts use a slightly different tapered seat profile than the standard aftermarket 60° conical; most owners running aftermarket wheels purchase aftermarket 60° conical lug nuts to match their wheel’s seat type rather than reusing OEM lug nuts.
18×9.5 ET38 with 245/40R18 or 255/35R18 tires, square setup, is the de facto standard flush configuration for the VA STI. This setup is documented on thousands of owner builds across the dedicated VA STI aftermarket community and has been the platform’s most popular spec since the chassis launched in 2015. At stock ride height with OEM-sized 245/40R18 tires, owners commonly report bolt-on fitment with no rolling required. With 255/35R18 tires the fitment is similar. With 265/35R18 tires, some owners report rear fender contact at full compression and recommend a precautionary fender roll, especially with lowered ride height. The setup clears both 4-piston (2015-2017) and 6-piston (2018-2021) front Brembos.
The Type RA wheel (19×8.5 ET55 BBS forged) is dimensionally identical to the standard 2018-2021 STI Limited 19″ wheel — different construction (forged vs cast) and different finish (gold), but same dimensions, same offset, same hub spec. It directly cross-fits any VA STI without modification. The S209 wheel is fundamentally different: 19×9 ET48 with the S209’s wide-body fenders. Bolting S209 wheels to a standard-body VA STI without the wide fenders results in significant fender protrusion — the S209 wheel was designed around the wide-body track and is approximately 7mm more outboard at the face than the OEM 19×8.5 ET55. Most S209 owners preserve original wheels for collectability and run aftermarket setups for daily driving.
Square only. The VA STI is all-wheel drive with a center differential that requires consistent rolling circumference across all four wheels — running staggered tire diameters or wheel widths stresses the center differential and can cause damage over time. All OEM VA STI configurations are square (front and rear identical), and aftermarket setups should follow the same approach. Within square setups, most aftermarket configurations use 18×9.5 ET38 or similar specs all around. Tire wear should be matched across all four corners through regular rotation; replacing only two tires at a time on this platform creates rolling circumference mismatches that affect AWD operation.
Yes — both 2015-2017 4-piston Brembos and 2018-2021 6-piston Brembos clear properly designed 18″ aftermarket wheels. The 6-piston caliper on 2018-2021 STIs is larger than the 4-piston, and some 18″ wheel designs with thick spoke profiles may have clearance issues — confirm caliper-to-spoke clearance before ordering. Most popular aftermarket options (18×9.5 +38, +45, +30) are documented as clearing the 6-pot Brembos without issue. 17″ wheels do NOT clear the 6-pot front calipers on 2018-2021 STIs — for winter or track wheels in 17″ diameter, you would need to retain pre-2018 4-piston brakes or use aftermarket calipers designed for 17″ clearance. 19″ wheels clear both calipers in any documented offset.
For OEM-equivalent fitment: 245/40R18 (matches OEM diameter on 2015-2017 STIs and 2018-2021 base/premium STIs) or 245/35R19 (matches 2018-2021 Limited, Type RA). For 18×9.5 +38 popular flush setups: 245/40R18 (most conservative), 255/35R18 (slightly shorter sidewall), or 265/35R18 (widest, may require fender roll). For aggressive 18×9.5 +22 setups: 255/35R18 or 265/35R18 with rear fender rolling. For 18×10.5 +21 stance builds: 245/35R18 or 255/35R18 stretched. Maintain identical tires across all four corners for AWD compatibility — tire diameter mismatches stress the center differential.
Three issues recur across the VA STI aftermarket community. First, the 56.1mm OEM hub bore is small relative to most aftermarket wheel center bore standards — if your aftermarket wheel has a 73.1mm center bore, hub-centric rings are mandatory to prevent vibration. Second, fender clearance with 265/35R18 tires depends meaningfully on tire brand: some brands (Michelin, Pirelli) run true to size while others (Falken, Federal) run wider — always verify clearance with your specific tire choice rather than assuming all 265s fit. Third, the 6-piston Brembo on 2018-2021 STIs does not clear all 18″ wheel designs — high-spoke-count or thick-profile wheel designs may have caliper interference. Always confirm caliper clearance with the wheel manufacturer for 2018-2021 STIs before ordering.
2015-2021 USDM. The VA chassis WRX STI launched for MY2015 and continued through MY2021 — the final year of the WRX STI in the United States. Subaru announced the discontinuation of the STI in 2020 alongside the retirement of the EJ257 engine. The 2022+ VB chassis WRX is sold without an STI variant in the US. The 2021 STI was offered in Base, Premium, and Limited trims, all sharing the same 6-piston Brembo brake package and 18×8.5 (Base/Premium) or 19×8.5 (Limited) wheels introduced with the 2018 refresh. There was no USDM “Final Edition” — the EJ25 Final Edition was a 75-unit global production limited to other markets. The VA STI guide does not apply to the 2022+ VB WRX, which uses different hardware.
At stock ride height, the most commonly documented aftermarket setups on the VA STI are 18-inch square configurations with offsets ranging from +38 to +45. For flush stance: the 18×9.5 ET38 setup with 245/40R18 or 255/35R18 tires is the de facto standard, documented on thousands of owner builds as bolt-on with no fender rolling required at stock height; the 18×9.5 ET45 setup is the conservative direct-fit option, documented with 245/40, 255/35, and 265/35 tire widths at stock height with no rubbing; the 18×8.5 ET30 setup keeps OEM rim width with a more aggressive offset and is documented bolt-on at stock height with 245/40 tires. For more aggressive stance at stock or moderately lowered ride height: the 18×9.5 ET22 setup typically requires rear fender rolling; the 18×10.5 ET21 setup requires rolled and pulled fenders plus stretched tires. All flush configurations clear both 4-piston (2015-2017) and 6-piston (2018-2021) front Brembos. Hub-centric rings (56.1mm vehicle / 73.1mm wheel) are required for any aftermarket wheel with a 73.1mm center bore. Square setups are mandatory on this AWD platform.
Every FMB build goes through two verification steps before anything is forged. First, our team runs a sanity check against your trim, brake package, and the configuration you’re ordering — comparing it to what’s commonly documented on similar VA STI builds, including the 4-pot vs 6-pot Brembo clearance, hub-centric ring requirements, and AWD circumference compatibility. If something falls outside what we’ve seen work on this platform, we flag it before moving forward. Second, our manufacturing partner verifies the wheel itself: backspace, brake caliper clearance for your specific brake package, hub fitment, and structural spec. You see the final design render and confirmed specs before production begins. Ride height, tire choice, and alignment are variables your installer handles on the car.