Wheel studs are not a glamorous upgrade. They do not add horsepower or improve lap times on their own. However, for any Subaru WRX or Subaru STI owner running a wheel and tire setup beyond stock, factory wheel studs are a weak point worth addressing before it becomes a problem. The ARP Wheel Studs Kit for Subaru WRX and STI replaces the factory studs with chrome moly fasteners rated to 190,000 psi tensile strength, giving the wheel mounting system the durability the rest of a performance build demands.
This post covers why the factory studs fall short, what the ARP kit provides, and which WRX and STI owners should prioritize this upgrade.
Why Factory Wheel Studs Are a Weak Point
The stock Subaru wheel studs are adequate for the factory wheel and tire combination at normal road loads. However, as wheel weight increases, tire grip improves, and driving becomes more aggressive, the demands on the wheel mounting system change significantly. Factory studs are made from a softer material than aftermarket performance alternatives and have lower tensile strength ratings. Under repeated high-load conditions, including hard cornering, track use, and aggressive street driving, factory studs can stretch, develop stress cracks, or fail outright.
Track use introduces additional stress through repeated thermal cycling. Brake heat transfers into the hub and studs during heavy braking zones, and the repeated expansion and contraction cycle weakens factory studs over time. Additionally, owners who frequently swap between track and street wheel sets accelerate wear on the factory studs through repeated installation and removal cycles. ARP studs handle both scenarios more reliably because the chrome moly material maintains its mechanical properties under the thermal and mechanical loads that track use generates.
Beyond strength, longer aftermarket studs also make wheel installation easier. The additional exposed thread length allows wheels to be guided onto the hub more safely during installation, which is particularly useful when changing wheels in a paddock environment or during a timed wheel swap.
What the ARP Kit Includes
The ARP Wheel Studs Kit for Subaru WRX and STI uses ARP’s 8740 chrome moly material, heat treated to 190,000 psi tensile strength. This is the same alloy ARP uses across their fastener lineup, including the head stud kits that are a standard upgrade on built EJ25 engines. The studs are cadmium plated for corrosion resistance, which matters for owners in humid climates or those who see wet conditions regularly.
The kit includes five studs per pack, covering one wheel position. Most WRX and STI applications use five lugs per wheel, so a full vehicle installation requires four packs. Lug nuts are not included. The thread specification is M12 x 1.25, which is the standard Subaru lug thread pitch. Fitment covers the Subaru WRX and STI from 1993 to 2012. Owners of 2013 and newer STI models or 2015 and newer WRX models should confirm fitment before ordering, as hub specifications may differ on later platforms.
Who Should Prioritize This Upgrade
ARP wheel studs suit any WRX or STI owner who uses the car on track, runs a heavier aftermarket wheel and tire setup, or regularly swaps wheels between street and track configurations. The upgrade is also a sensible precaution for high-power builds where the additional torque and grip levels put more lateral load through the wheel mounting system than the factory studs were designed to handle.
For street-only builds running stock or light aftermarket wheels with no track use, the factory studs are generally sufficient. However, because the installation cost is low when done alongside other hub or suspension work, many owners include the ARP stud upgrade as a preventative measure during corner weight adjustments, brake work, or coilover installation. Combining the install with existing wheel-off work avoids duplicating labor later.
Owners running coilovers or lowering springs who corner more aggressively than stock will also benefit. Improved suspension geometry and stickier tires generate higher lateral loads at the hub, and upgrading the studs matches the fastener strength to the increased demands of the modified suspension setup. The coilovers category at Wrench Masters covers suspension upgrade options for WRX and STI owners who are also at this stage of the build.
ARP Wheel Studs and the Broader WRX and STI Build
Wheel studs fit into a category of upgrades that are easy to overlook because they do not directly add power. However, they are part of a reliable build foundation that allows the rest of the modifications to perform safely. A high-power, track-capable STI running stock wheel fasteners is carrying a preventable risk at the hub. Addressing that risk early keeps the focus on performance rather than roadside repairs.
For STI owners who are further along in their builds and thinking about the full picture of what a track-capable car needs, the STI performance upgrade guide covers the build sequence from bolt-ons through engine builds. WRX owners can find the equivalent planning resource at the WRX performance upgrades hub.
For owners who are also addressing brake system reliability alongside the wheel stud upgrade, the wheel studs category and the cooling upgrades post cover the thermal management side of track preparation that often gets addressed at the same time as hub fasteners.
Installation Notes
ARP wheel stud installation on the WRX and STI requires pressing the factory studs out of the hub and pressing the new ARP studs in. This process typically requires a hydraulic press or a dedicated stud installation tool. Attempting to pull studs in using the lug nut method risks damaging the new stud threads or hub surface. For owners having the work done professionally, the installation is straightforward for any shop familiar with the Subaru platform.
Because nuts are not included in the kit, owners running extended studs for track use should confirm that the lug nuts in use have sufficient thread engagement on the longer stud length. The lug nuts category at Wrench Masters includes compatible options for WRX and STI applications if new hardware is needed alongside the stud upgrade.
Shop ARP Wheel Studs for Subaru WRX and STI
The ARP Wheel Studs Kit is in stock and ships in 24 to 48 hours. Priced at $44.73 per pack of five studs.
0 Comments for “ARP Wheel Studs for Subaru WRX and STI”