2015-2021 VA Subaru WRX / STI Wheel Fitment Guide

The fourth-generation VA-chassis Subaru WRX and STI (2015-2021) represent a significant evolution in Subaru’s performance sedan lineage. Unlike previous generations, Subaru chose to stop marketing the WRX and STI under the Impreza name to remove the perception of being married to the standard Impreza economy car. The VA chassis was engineered with a longer wheel base in mind and higher quality materials throughout than its predecessors. This shift included the adoption of the 5x114.3mm bolt pattern across all WRX and STI models, unifying the platform and unlocking access to a vast catalog of aftermarket wheels.

The VA-chassis WRX and STI (2015-2021) share identical wheel fitment specifications, suspension geometry, and body constraints. All wheel recommendations and fitment data apply to both models. The primary distinction is brake clearance. From 2015-2017, the STI came with 4-piston Brembo calipers. 2018+ STI models (2018-2021) feature 6-piston monoblock Brembo calipers with 340mm rotors that require minimum 18” wheels due to radial caliper height. Note that the 2018 WRX Performance Package featured red painted calipers. These were not Brembos and were the same caliper as the standard WRX. The 2018+ STI brakes present more of a concern for caliper fitment than either the 4-pot or standard calipers.

OEM / Stock Wheel Specifications

All VA-chassis WRX models share identical wheel specifications regardless of trim level.

Factory Wheel Configuration

The OEM wheel selection has some interesting brake clearance variations across the platform. The 17” WRX wheels found on early models (2015-2017) will not clear the larger STI Brembo brakes, limiting their use to base WRX models. The 18x8.5” wheels introduced on 2018-2019 WRX Premium and Limited trims, while larger in diameter, do not clear STI Brembo calipers. The 2020-2021 generation Premium and Limited wheels do clear the brakes, especially convenient if looking for another wheelset for winter duties.

The 19” STI wheel presents an interesting reversal: while adequate for STI’s 6-piston Brembo system, fitting these wheels to WRX models equipped with 4-piston Performance Package brakes requires a 5mm spacer to avoid caliper interference. Another final consideration when piecing together OEM wheels across model years. The gunmetal finish used on 2018-2019 wheels differs slightly in shade from the 2020-2021 specification, creating visible mismatches if combining wheels from different production periods in addition to their varying internal profile.

The 5x114.3 Transition

For nearly two decades, Subaru’s WRX performance lineup was mechanically divided by hub architecture. The WRX historically utilized a 5x100mm bolt pattern, while the STI adopted the larger 5x114.3mm pattern from 2005 onward. This bifurcation restricted aftermarket wheel availability for WRX owners and the inability to purchase STI takeoffs.

The VA chassis unified the platform. All 2015-2021 WRX and STI models utilize the 5x114.3mm bolt pattern and the same hub centerbore. This decision was driven by the need to support higher curb weights and increased lateral grip potential. The larger bolt circle diameter reduces shear moment applied to individual wheel studs during cornering and braking events. For end-users, this unlocks the entire catalog of wheels designed for platforms like the Mitsubishi EVO, Nissan 350Z/370Z, and other high-performance Japanese vehicles.

Aftermarket Considerations

Scrub Radius and Suspension Geometry

The most frequently overlooked variable in aftermarket wheel selection is the alteration of suspension geometry. Scrub radius is the distance at ground level between the tire’s centerline and the steering axis inclination line. The VA WRX is designed with high positive offset (+55mm) to achieve a slightly negative or near-zero scrub radius. The standard aftermarket fitment for the VA chassis is 18x9.5” +38mm. This moves the mounting face 17mm inboard relative to the wheel centerline, pushing the wheel assembly 17mm outboard and introducing a 17mm increase in positive scrub radius. This change results in a number of changes in vehicle dynamics:

• Steering Feedback: Increased lever arm means road forces exert significantly more torque on the steering rack, showing up as kickback or steering wheel fight
• Tramlining: The car becomes more sensitive to longitudinal ruts in pavement, requiring additional steering input for correction
• Movement Under Braking: Under hard braking on uneven surfaces, the increased positive scrub radius amplifies pull toward the side with more grip
• Component Fatigue: Creates cantilever effect applying constant bending moment to the hub bearing unit, accelerating wear intervals

These are common consequences that enthusiasts regularly deal with which out much thought. It is, however, important to understand that more aggressive offsets will likely trades straight-line stability and steering precision for increased track width and tire contact patch.

Fender Rolling Requirements

The rear quarter panel architecture presents additional challenges. Unlike older chassis with single-layer lips, the VA features double-walled construction with a spot-welded inner wheel house and outer quarter skin. This makes the fender lip much more rigid. To roll these fenders flat without cracking the paint:

• Maintain surface temperature between 120°F and 140°F using a heat gun to increase clear coat and base coat elasticity
• Use a hub-bolted fender roller tool
• Apply steady force to avoid uneven, wavy bodywork

For aggressive fitments (18x9.5” +38mm or lower offsets), fender rolling is typically required to provide clearance for wider tires.

Brake Clearance Profiles

The VA chassis was equipped with three distinct brake calipers, each presenting unique spatial challenges. Wheel clearance depends not just on diameter, width, and offset, but critically on spoke design and barrel depth.

1. Standard Floating Calipers - WRX Base / Premium / Limited: 2-piston sliding caliper front and 1-piston sliding rear. These compact calipers float inboard of the rotor face and virtually any aftermarket wheel with an appropriate offset for the VA WRX should clear without issue. The Optional Performance Package had identical calipers, but painted red and loaded with performance brake pads.

2. Brembo “Red” 4-Piston - 2015-2017 STI: 4-pot fixed caliper front and 2-pot fixed caliper rear. These fixed calipers utilize opposing pistons on both sides of the rotor. The outboard pistons necessitate a caliper body that protrudes significantly toward the wheel spokes. These 4-piston units sit relatively close to the hub center where wheel spokes are typically thickest. Wheels with flat face profiles or deep lips often fail to clear these calipers even with correct offset, for example, Enkei RPF1 in 18x9.5” +38. Despite having a “correct” fitment spec, the wheel’s flat spokes interfere with the 4-piston Brembo caliper. Another example is the OEM 19” STI wheel which requires a 5mm spacer to fit over the 4-pot Brembos.

3. Brembo “Neon/Silver” 6-Piston - 2018-2021 STI: 6-piston fixed monoblock caliper front and 2-piston fixed caliper rear. The shift to 6-piston calipers and larger 340mm rotors led Subaru to specifying a 19” wheel for OEM STI fitment. While many 18” wheels will fit, most 17” wheels will be incompatible due to the radial height of the caliper rubbing the inner barrel. Interestingly, the 6-piston caliper is slightly narrower in profile than the older 4-piston unit, sitting further out radially where wheel spokes tend to thin out. Some wheels that clear the 6-piston STI brakes do not clear the 4-piston WRX Performance Package brakes. When in doubt, verify brake clearance with the wheel manufacturer.

Rear Camber Adjustment Constraint

A significant limitation of the VA chassis suspension is the lack of factory rear camber adjustment. The rear multi-link suspension relies on fixed-length lower control arms. Camber is determined solely by ride height and manufacturing tolerances. The factory eccentric bolts only offer minute toe adjustments. For any aggressive fitment (9.5” width and +38mm or lower), aftermarket rear lower control arms are essentially required. These adjustable arms allow the alignment technician to dial in precise negative camber (typically -2.0° to -2.5°) to pivot the top of the tire inboard, clearing the fender lip.

Load Rating Considerations

The VA WRX has a curb weight of approximately 3,267 lbs for the Base model. Higher trim levels were heavier. Gross axle weight ratings are approximately 2,370 lbs front and 2,293 lbs rear. This translates to a minimum load rating requirement of approximately 1,200 lbs (544 kg) per wheel. Most reputable wheel manufacturers offer load ratings well above this threshold. That said, if you are buying wheels from a manufacturer that cannot provide load rating information, it’s best to look elsewhere. Any quality wheel manufacturer will publish this data.

Hub Centric Rings

Most aftermarket 5x114.3 wheels are designed with 73.1mm center bores for universal fitment across multiple vehicle makes. The VA WRX requires 56.1mm hub centering. Use hub centric rings to adapt these wheels. Aluminum rings are strongly recommended over plastic for track use, as brake heat can deform plastic rings over thermal cycling.

TPMS Compatibility

The VA-chassis WRX (2015-2021) utilizes a 315MHz TPMS system. When purchasing aftermarket wheels, you can reuse your existing TPMS sensors. However, note that the VB-chassis WRX (2022+) uses a 433MHz TPMS system, which is incompatible with VA sensors. If migrating wheels between VA and VB generations, TPMS sensors must be replaced to maintain system functionality.

Wheel Recommendations

Below are recommendations based on suspension constraints, brake clearance profiles, and real-world experience from the VA WRX community. These are general recommendations focused on wheel dimensions and offset ranges. Wheels with different spoke designs and barrel profiles may fit differently. Always verify fitment for your specific setup and brake package.

OEM+ Recommendations

Conservative sizes that maintain or slightly improve upon factory specifications without requiring body modifications or significant geometry changes. These sizes work well for daily drivers, winter setups, or owners prioritizing reliability and OEM-like handling characteristics.

These conservative sizes provide maximum clearance margins, require no body modifications, and work on stock suspension. They maintain the factory scrub radius design, preserving straight-line stability and steering precision. Excellent choices for winter wheel setups or owners seeking weight reduction without fitment compromises.

Aggressive Street Recommendations

The optimal balance of performance, aesthetics, and fitment ease, the 18x9.5” +38mm configuration is widely regarded as the enthusiast sweet spot for the VA platform. It provides substantial track width increase, accommodates high-performance 265-section tires, and achieves flush fitment with the fender arch. However, this specification is not a zero-compromise solution. It introduces increased positive scrub radius (affecting steering feel and braking dynamics), typically necessitates fender rolling, and requires rear camber adjustment via aftermarket control arms to prevent fender contact with wider tire compounds.

Track / Competition Recommendations

At this level of preparation, aftermarket coilovers and camber plates are mandatory. These setups are best suited for the track junkies who choose maximum mechanical grip over street manners and component longevity concerns.

Additional Resources

• Tire Compatibility: See the VA WRX Tire Guide for tire size recommendations, diameter calculations, and load ratings
• Quick Reference: VA WRX Wheel and Tire Cheatsheet for validated wheel and tire pairings
• Where to Buy: Tire Rack for tires with nationwide network of recommended installers

Remember: Actual fitment varies based on wheel design (spoke profile, barrel shape), tire selection, suspension setup, ride height, camber, and fender condition. Always verify fitment for your specific combination and brake package before purchasing. For aggressive fitments, budget for rear lower control arms and fender rolling as mandatory supporting modifications rather than optional extras. All information provided is based on extensive research and community trial and error. Please evaluate and verify fitment data at your own discretion. As always, modify at your own risk.