APEX ARC-8 | 18" x 8.5" ET38 | 5x120mm | 72.56mm

Need help selecting the proper wheel fitment for your BMW? APEX Race Parts have tirelessly test-fitted hundreds of setup combinations in order to provide direct-fit, spacer-free wheel packages for everything from showroom-fresh cars to all-out race builds. Their detailed fitment guides help you avoid costly trial-and-error and walk you through every step of finding your perfect setup.

Fit Matters

An optimized car setup begins with the perfect wheel and tyre fitment. Without model-specific attention to each wheels specifications, maximum performance is compromised. Each size was selected to find the right balance between a clean fit and the most grip possible. The ARC-8's wide range of widths, diameters, offsets and face profiles result in unique fitments ranging from 8.0" to 10.5" wide. Each wheel combines these features to meet the different brake caliper, strut, and fender clearance needs of each BMW model. Most vehicle models have options for wheels that range from direct-fit to aggressive for specialty applications. Daily drivers and professional racers don't have the same needs, so why should they be forced to buy the same exact fitment?

The ARC-8 wheel is available in two unique face profiles. The shallower face provides increased caliper clearance on narrow applications, while the deeper concave face reduces weight and creates a stunningly aggressive appearance on low offset and wide width applications. These two face profiles are available in all 17", 18" and 19" diameters.

The spokes of the ARC-8 were designed to be robust where they need to be and extra lightweight where they can be. The split "Y" spokes were carefully evaluated from every aspect to ensure light weight and remarkable strength. The lack of a deep front lip and spokes that connect directly to the barrel's lip create a rigid wheel with even load distribution. These features help reduce one of the most common concerns with aftermarket wheels — bending. Beauty follows function with this extremely popular design, as it adapts perfectly to both flat and concave versions.

If the spokes of a wheel don't clear your brake calipers, then the wheel can't turn. APEX made sure the spokes on all 18" APEX wheels properly clear all OEM brake calipers, spacer free. Because of the large variation in clearance needs, APEX produced the ARC-8 wheel using two unique face profiles. When the correct profile is used for each specific vehicle application, most Big Brake Kits fit behind the 18" spokes, although a few applications will need a thin spacer due to the added width of aftermarket calipers. The flatter face profile offers maximum caliper clearance for high offset, narrow wheels, and older vehicles with Big Brake Kits. The deeper 18" concave face still has enough room to clear wider aftermarket Big Brake Kits on almost all applications, as APEX designed the spoke profile to require a thin spacer only in a few rare situations. Contact us to confirm brake clearances for your specific application.

Spoke clearance is only half the problem. The barrel opening on a wheel also needs to be big enough to clear the sides of your caliper and rotor. Not all 18" wheels are made equal though. APEX designed the ARC-8's barrel to open to it's largest diameter as early as possible. The sooner this happens and the wider it opens, the larger the brake kit you can fit. This is vital on 18" applications because without enough clearance, most larger diameter brake kits will almost certainly not fit behind typical wheels. Most 18" wheels on the market make aesthetic compromises to their design that consumers wouldn't even know have a major negative impact on barrel clearance. Those wheels may work with smaller stock brakes, or smaller diameter Big Brake Kits, but the larger kits will pose a major problem. APEX 2D modeled most Big Brake Kits available in Solidworks and altered the wheel design to clear as many kits as possible. The 18" ARC-8 wheels can clear some 380mm kits, and everything smaller clears the barrel with ease. Contact us to confirm brake clearances for your specific application.

Race wheels can't just be light, they need to function in a high performance environment. Unlike the narrow lug recesses of most other wheels, the ARC-8 wheel boasts a completely wide-open design that easily fits over-sized race lugs and beefy impact sockets. This allows for quick and easy wheel changes at the track, and as a bonus prevents chips and scratches from tools for those just running these wheels on the street.

All ARC-8 wheels are purpose built for select vehicle applications, and centering rings are never required for any BMW application. All 5x120mm bolt pattern wheels feature a direct-fit 72.56mm centre bore.

APEX don't reuse one cap design for all their wheels. Every ARC-8 wheel is designed to work with factory centre caps. You can easily replace APEX centre caps with OEM roundels for a clean factory look. The ARC-8 wheel will come with either a carbon-look centre cap or the redesigned, Gloss Black centre cap that mimics the size and shape of a BMW factory centre cap.

The ARC-8 wheel can be used with all OEM and aftermarket mounting hardware with a 60° tapered seat. Lug bolts, wheel locks, and stud conversion kits all work perfectly. The ARC-8 wheel also accepts wheel spacers without issue. The shallow rear chamfer allows the wheel to remain hub centric even when 5mm flat spacers are used. The chamfer is deep enough to clear the chamfered lip some aftermarket spacers have that would typically cause improper seating and wheel vibration.

TPMS sensors, which monitor tyre pressure, are one piece of technology that can't be compromised. The attention to OEM compatibility on the ARC-8 wheel doesn't end with centre caps. All APEX wheels accept OEM and aftermarket equivalent BMW TPMS sensors, and any standard sized metal or rubber valve stem.

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These APEX wheels are produced using a manufacturing process known as flow forming. This process significantly reduces weight in the barrel, which has the greatest impact on rotational mass. During the manufacturing process, rollers apply high pressure to the inner barrel, compressing the aluminum into its final shape. This effectively eliminates porosity and aligns the grain structure of the metal, which increases tensile strength. The end result is a lightweight and extremely strong barrel that equals that of a traditional forged wheel at a fraction of the cost.

Many companies promote their wheels as being certified by the VIA when they actually aren’t. That’s like using the USDA logo on food without permission. APEX wheels get officially tested and registered by the VIA in Japan, and they have the proof to back it up.

Japan’s JWL is a commonly followed standard for wheel load ratings. The APEX flow formed wheels meet, and most exceed, their load rating requirements. Most manufacturers only meet the minimum while some don’t even do that. Check and verify load ratings before you buy.

Various design features were implemented to ensure that the ARC-8 wheel design was as light and durable as possible. APEX began with a strong one-piece design featuring an open hub centre and reliefs in the mounting pad to remove weight between lug holes. The design was then run through Finite Element Analysis (FEA) to further optimize the spoke and barrel design. The result is a light weight wheel with extra strength in all the right places, while keeping weight to a minimum.

The ARC-8 wheel is available in multiple finishes, in addition to exclusive finishes available only through select dealers. All APEX wheels are finished using a comprehensive multi-stage liquid paint system over a powder coated base coat. Standard finishes include gloss metallic finishes, and semi-gloss or matte finishes. Hyper finishes include an additional coating of a premium liquid-like metallic silver to create a uniquely bright finish that can only be achieved through misting liquid paint.

Often overlooked, painted or powder coated lug hole seats can cause hardware to loosen or begin the spread of chipping the paint to more visible sections. The ARC-8 wheel's coating process leaves lug holes, centre bores and mounting pads unpainted, which ensures proper fit and torque values.

APEX wheels now come with a lifetime structural warranty and 1 year finish warranty, so you can be confident in your purchase. 

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