The Audi S4 B8 uses 18x8-inch wheels as the stock setup (ET43) with 245/40R18 tires, 5x112 bolt pattern, and a 66.6 mm center bore. Some trims offered 19-inch wheels as an option, and aftermarket sizes are common up to 20 inches, but always verify fitment for your exact VIN and brake setup.
The B8 S4 production spanned 2008–2012 (with some markets extending into 2013). Wheel options varied by year, trim, and package, so this guide covers the baseline factory spec and widely used aftermarket sizes, along with practical fitment considerations for upgrades. Accurate fitment depends on your specific car’s configuration, including brakes, suspension, and fender clearance.
Stock wheel sizes (B8 S4, 2008-2012)
The following are the official baseline measurements for the standard configuration of the B8 S4. These dimensions are useful when sourcing replacement wheels or planning a factory-style upgrade.
- Wheel diameter: 18 inches
- Wheel width: 8 inches
- Bolt pattern: 5x112 mm
- Offset (ET): ET43
- Center bore: 66.6 mm
- Tire size (recommended): 245/40R18
For most drivers, the essential baseline is 18x8 ET43 with 245/40R18 tires. This pairing maintains the intended ride quality and clearance from the factory setup.
Fitment considerations
When upgrading from stock, consider brake caliper clearance, fender clearance, and suspension geometry. Moving to 19- or 20-inch wheels often requires adjusting offset, using spacers, or choosing narrower tire widths to avoid rubbing. Always verify clearances and, if possible, consult a wheel fitment chart specific to your VIN.
Common aftermarket sizes and fitment scenarios
Many owners upgrade for aesthetics or performance. The following are common directions and typical ranges seen in the enthusiast community. Exact fitment depends on year, trim, and any brake changes from options packages.
- 19-inch wheels: common widths range from 8.5" to 9.0"; typical tires include 235/35R19 or 255/35R19, with offsets generally in the mid-30s to mid-40s (ET35–ET45).
- 20-inch wheels: common widths around 9.0" to 9.5"; tire options include 235/30R20, 245/30R20, or 265/30R20, with offsets typically in the 30s to 45s range depending on caliper clearance.
- Wider or track-focused setups: 9.5"–10" widths on 20" wheels with low-profile tires; these require careful brake clearance and potential fender work.
When upgrading, confirm fitment with a test fit or measurements, and plan for potential adjustments to maintain correct speedometer readings and suspension alignment. Using reputable wheel brands and ensuring proper hub-centric centering can reduce vibration and improve drivability.
Practical tips and maintenance
Key steps before purchasing or mounting new wheels include verifying bolt pattern compatibility (5x112), hub bore, and center bore, as well as checking brake clearance (especially around larger calipers) and fender clearance. Keep the overall diameter within a small percentage of stock to preserve gearing and speedometer accuracy. Consider professional installation for complex upgrades or if moving to very large wheels.
Conclusion
The Audi S4 B8’s baseline rim size is 18x8 inches with ET43 and 245/40R18 tires, using a 5x112 bolt pattern and a 66.6 mm center bore. Optional 19- and 20-inch wheels are common aftermarket choices, but fitment depends on year, trim, and brake configuration. Always verify VIN-specific wheel charts and measure clearance before purchasing or mounting wheels.
Summary
Stock rim size for Audi S4 B8: 18x8 inches, ET43, 66.6 mm hub bore, with 245/40R18 tires, 5x112 bolt pattern. Optional 19- and 20-inch wheels are widely used in the aftermarket, but exact fitment varies by year and brake setup. Always confirm compatibility for your vehicle configuration and consult a professional if unsure.