WRX STI Wheel Size | Factory Specs By Year

The bolt pattern on a 2004 WRX STI won’t fit a 2018 model — and that’s just one of the differences that makes knowing your generation’s exact WRX STI wheel size critical before buying replacements. Wheel specs changed significantly across the STI’s generations, from the 5×100 bolt pattern on early cars to the 5×114.3 pattern used on every STI since 2008. Offset, width, and factory tire profiles all shifted between years, so bolting on wheels from a different generation can cause rubbing, poor handling, or unsafe fitment. Here’s exactly what each generation came with from the factory, plus what actually works for aftermarket upgrades.

Factory Wheel Specs By Generation

Subaru used three distinct factory wheel setups across the STI’s production run, plus a fourth for the related WRX Limited trim that shares the same chassis. The table below covers the stock specs for each generation, including bolt pattern, offset, and original tire size.

Every STI generation shares a 56.1mm hub bore and M12x1.25 lug threads. The 2004 model’s 5×100 bolt pattern is the single biggest compatibility gate — wheels from any 2008 or newer STI simply won’t mount on it without adapters. FastWRX’s Subaru wheel information guide confirms these factory specs across generations and notes that tire sizes shifted to keep overall diameter consistent as wheel diameter grew.

What Aftermarket Wheel Sizes Actually Fit?

The most popular aftermarket upgrade on the 2015–2021 VA-chassis WRX and STI is 18×9.5 inches with a +38mm offset, paired with 255/35 or 265/35R18 tires. This setup fills the wheel wells more aggressively than stock and improves cornering grip without requiring major body modifications on most cars. Conservative builds staying closer to factory geometry run 18×8.5 or 18×9.0 wheels with offsets between +45 and +55mm, which clear the factory Brembo calipers and work at stock ride height with zero rubbing.

Wider street setups push to 18×10 +38 or +40, but that range typically needs fender rolling and may require adjustable camber arms to fit cleanly without scrubbing. On the earlier 2004 and 2008–2017 cars, 17×9 wheels with +35 to +40 offset are a common budget-friendly track option that clears big brakes when the barrel design cooperates. If you’re ready to shop, our roundup of the best WRX STI wheel options covers top picks across budgets with generation-specific fitment notes.

What Should You Check Before Buying Wheels?

Three mistakes cause most fitment headaches on these cars. First, the bolt pattern mix-up: 2004 STIs use 5×100, while every 2008+ STI uses 5×114.3 — buying the wrong pattern means the wheel simply won’t mount. Second, ignoring hub bore differences: most aftermarket wheels come with a 73.1mm center bore, which requires hub-centric rings with a 56.1mm inner diameter to center the wheel properly and prevent vibration. Third, overlooking brake clearance — STI Brembo calipers are large, and some aftermarket wheels, especially narrower or lower-offset designs, contact the caliper or need spacers to clear.

Always confirm caliper clearance with the wheel vendor before ordering, particularly for 17-inch wheels on 2008+ STI models where clearance is tightest. To verify your own car’s exact specs, check the driver-door jamb placard for the factory tire size and recommended pressures, then confirm your trim and model year against the table above. Trim levels within the same year sometimes carry different wheels, so the VIN or door sticker is the final word.