About This Audi S4 Premium Plus 2015 Build
We love featuring real builds from real owners. This Audi S4 Premium Plus 2015 sits on a set of 18×8.5 / 18×8.5-inch Radi8 R8cm9 wheels, and the result speaks for itself.
The owner chose Radi8 for a reason. This brand delivers serious quality and a design language that turns heads at every car meet. We see hundreds of Audi S4 Premium Plus builds come through WheelFront every month, but this one stands out. The combination of the exterior with the Radi8 R8cm9 creates a look that balances aggression with elegance.
Fitment Breakdown: Radi8 R8cm9 on the Audi S4 Premium Plus 2015
I walked around this B8.5 S4 for twenty minutes at the show, and I keep coming back to these Radi8 R8cm9 wheels. The 18x8.5 setup is a smart choice for the Audi platform. It keeps the rotational mass down while giving the car a purposeful, track-ready aesthetic.
We see a lot of people go too wide, but the +35 offset here is perfection. It pushes the face of the wheel right out to the edge of the fender line without requiring a sledgehammer to the metal. You get that aggressive stance without sacrificing the clean lines of the S4.
Caliper clearance on the S4 is always a headache because of those massive factory binders. These Radi8s clear the stock hardware easily. You do not need to hunt for spacers or custom adapters to make this fit work.
The hub bore sits perfectly flush against the Audi mounting surface. We always preach proper centering to avoid those highway vibrations. This setup feels locked in and stable at any speed.
The spoke design on the R8cm9 is wild, with those deep, twisting blades that pull your eye toward the center cap. Because we are looking at an 18-inch wheel, you get just enough barrel lip depth to add some character. It looks way more complex than a standard multi-spoke design.
Since the owner installed air suspension, this fitment changes throughout the day. When it is aired out, the wheels tuck neatly into the arches. It creates a seamless look that makes the car appear glued to the pavement.
Watch out for rubbing if you drive low on a daily basis. The front liners might kiss the tires during full lock turns if you drop it too far. Keep your dampening firm to avoid any unwanted contact with the fender lips.
What We Recommend for Audi S4 Premium Plus 2015 Owners
If you own a B8.5, stop over-engineering your wheel choice. An 18x8.5 or 19x9 setup is the sweet spot for these cars. Anything wider than a 9.5 starts to ruin the handling geometry that makes the S4 so fun to drive.
Stick to a square setup whenever you can. Staggered wheels on an AWD Audi platform are a recipe for differential nightmares and uneven tire wear. Keep your diameter and width identical at all four corners to keep that Quattro system happy.
Offset is your best friend when you want that flush look. Stay between +30 and +40 for the best results on an 8.5-inch wide wheel. If you go lower than +30, you will likely poke too much and end up throwing rocks at your own paint.
Do not be afraid of a mild tire stretch if you want to dial in your stance. A 235 or 245 width tire on an 8.5-inch rim gives you just enough sidewall flex to look aggressive. Just remember that too much stretch is a death trap for your rims on potholes.
The biggest mistake we see is people buying wheels with the wrong center bore. Always double-check that your wheels are hub-centric for the Audi 66.6mm requirement. Dealing with hub rings is a chore that you can easily avoid with the right order.
Style and Build Analysis
The Machined Black finish on these Radi8s is a masterclass in contrast. The bright, machined surfaces catch the light while the black inner windows disappear into the shadows. It makes the wheel look like a piece of functional sculpture rather than just a circle of aluminum.
When the sun hits these wheels, the geometry really pops. The twisting spokes create a sense of motion even when the Audi is parked. It transforms the S4 from a subtle sleeper into something that commands attention at every light.
I compare this to a lot of the flat-faced wheels we see at meets. Most people choose a safe, concave design, but the R8cm9 is bold. It demands that you look closer to understand how the design folds into the center.
The proportions are spot on for the B8.5 chassis. The wheels do not overwhelm the body, nor do they look like they are hiding inside the fenders. It is a balanced approach that respects the Audi's original design language.
This build proves that you do not need a widebody kit to make a car look custom. Good suspension and the right wheel choice go a long way. The car feels complete, refined, and entirely intentional.
Why We Love This Build
This S4 is the definition of a well-executed street build. The air suspension drops the body over the Machined Black wheels until the fitment is razor-thin. When the car sits on the ground, the light hits those complex spokes and creates a look that is aggressive yet sophisticated. It is the kind of car that makes you look back every time you walk away.
We love this because it does not try too hard. Every choice serves the overall aesthetic of the platform. If you want a car that turns heads without being loud, this is your blueprint. Get the right offset, drop the suspension, and just drive. This is exactly how an S4 should look.
Full Specs Breakdown
Here is exactly what this owner is running. We break down every detail so you can replicate this build or use it as a starting point for your own setup.
- Car Make & Model: Audi S4 Premium Plus 2015
- Vehicle Color:
- Wheel Brand & Model: Radi8 R8cm9
- Wheel Size: 18×8.5 / 18×8.5
- Offset: 35 / 35
- Wheel Finish: Machined Black
- Tires: Provider Entrada 225/35 24.2″x8.9″ / 225/35 24.2″x8.9″
- Suspension: Air Suspension
Before You Buy: Fitment Checklist
We talk to Audi S4 Premium Plus owners every day. These are the questions we hear most before they pull the trigger on new wheels.
Will 18×8.5 / 18×8.5-inch wheels fit my Audi S4 Premium Plus? Yes, but fitment depends on width, offset, and tire size working together. A wrong offset means rubbing. A wrong tire size means poor handling. Always verify all three.
Do I need to modify my fenders? That depends on your offset and suspension. A conservative offset with stock ride height usually fits without modification. Go aggressive and you may need to roll or pull your fenders.
Can I daily-drive this setup? Absolutely. Thousands of Audi S4 Premium Plus owners run 18×8.5 / 18×8.5-inch wheels every day. The key is choosing the right tire with enough sidewall to absorb road imperfections.
