OEM wheel and tire fitment specs for the 2008 Audi S4, including bolt pattern (PCD), center bore diameter, thread size, rim diameter, rim width, wheel offset, and backspacing.
Recorded OEM specifications for the 2008 Audi S4, donor years with overlapping ranges, and a calculator to compare a selected wheel. Range overlap is not a guaranteed fit.
Center-bore records disagree: year-level hub 66.6 mm vs trim range 57.1–57.1 mm. Interchange below does not treat this as an unqualified match.
Thread-only product links are shopping examples, not verified fits. Seat style is not confirmed here. As an Amazon Associate we earn from qualifying purchases.
Donor vehicles with overlapping OEM specs
These are vehicle-year records whose recorded OEM ranges overlap this 2008 Audi S4. Overlap is not a guarantee that a specific wheel will install. Selected-wheel comparison is in the calculator below.
Evaluated 320 donor years. Listed 24 eligible overlaps (not all evaluated years are compatible). Showing all listed.
Hub-centric rings of about 66.5 → 57.1 mm mm may be relevant if the wheel bore is larger than the hub; they cannot enlarge a smaller bore. Approximate position vs the mid OEM package: outer change -1.17 mm, inner change -5.18 mm. This uses aggregated width/offset ranges, not a specific wheel.
Hub-centric rings of about 66.5 → 57.1 mm mm may be relevant if the wheel bore is larger than the hub; clearance is not verified. Donor width/offset sits outside the known OEM envelope for this vehicle.
Wheel geometryOEM width/offset ranges overlap (not a specific wheel)
Center-bore records disagree (target year-level hub 66.6 mm vs trim range 57.1–57.1 mm; donor year-level hub 66.6 mm vs trim range 57.1–57.1 mm). Unqualified overlap is not claimed until the conflict is resolved. Approximate position vs the mid OEM package: outer change -1.17 mm, inner change -5.18 mm. This uses aggregated width/offset ranges, not a specific wheel.
Hub-centric rings of about 66.5 → 57.1 mm mm may be relevant if the wheel bore is larger than the hub; they cannot enlarge a smaller bore. Approximate position vs the mid OEM package: outer change -2.18 mm, inner change -4.18 mm. This uses aggregated width/offset ranges, not a specific wheel.
Audi S4 Years With Compatible Wheels
Only years with evidence-based interchange relationships are listed. Adjacent years are not assumed compatible.
Compare a donor vehicle or custom wheel against this 2008 Audi S4. Use Compare in calculator on a donor row above to fill the donor side of this same calculator.
Compare
Compare wheel compatibility between two vehicles
Wheels from (donor vehicle)
Selected Car:
Custom wheel size (optional)
Tip: change values here to simulate custom wheels and immediately see the impact in the comparison below.
Custom tire size (optional)
Installed on (your vehicle)
Selected Car:
2008 Audi S4
Compare Rims
Specification
Wheels from
Installed on
Result (Click it)
Bolt Pattern
The total number of bolt holes and the diameter of the circle they form.
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5x112
Center Bore
The hole in the center of the wheel that fits over the vehicle’s hub.
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57.1 mm
Thread Size
The size and spacing of the threads on the bolts or nuts that hold the wheel in place.
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M14 x 1.5
Rim Diameter
The wheel diameter in inches that determines which tire sizes will fit.
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18"
Rim Width
The distance between the inner edges of the wheel is measured in inches.
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8.0"
Wheel Offset
How far the wheel sits inward or outward relative to the hub mounting surface.
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45 mm
Backspacing
Shows how much space the wheel takes up toward the inside of the vehicle.
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-
Wheel Fasteners
The type of hardware used to secure the wheel to the vehicle.
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-
Compare Tires
Specification
Wheels from
Installed on
Result (Click it)
Section Width
The width of the tire from sidewall to sidewall, measured in millimeters.
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-
Aspect Ratio
The height of the tire’s sidewall expressed as a percentage of its width.
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Diameter
The wheel diameter for which the tire is designed to fit.
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Tire Pressure
The recommended air pressure for safe and efficient driving.
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Overall Diameter
The total height of the tire and wheel combined affects clearance and speedometer accuracy.
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-
Wheel Fitment Parts for the 2008 Audi S4
Example products matched to recorded thread, hub, or spacer dimensions. They are not verified fits. Confirm seat style, thickness, and clearance before ordering.
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2008 Audi S4 Wheel Fitment Guide
Think of this as a clear, safety-first quick recap for picking wheels and tires that actually fit your 2008 Audi S4. I’m using the known OEM specs below and the on-page calculator at wheelinterchange.com to keep things grounded and easy to verify.
1. Misconception
Any 5x112 Audi wheel will fit a 2008 S4 without issues.
2. Why it seems true
A lot of Audi models share the 5x112 bolt pattern. Listings and forum posts often say “it bolts right on.” Photos look fine from the outside. It’s easy to assume the rest will sort itself out.
3. What is true
Fitment is more than bolt pattern. You need the correct center bore, offset, width, and tire diameter. You also want proper thread engagement on the lug bolts and hub-centric support. Spoke design and brake clearance matter too, and those are not guaranteed by the numbers alone.
Spec
2008 Audi S4 (known OEM baseline)
Bolt pattern
5x112
Center bore
66.6 mm
Thread size
M14 x 1.5
Rim size
18 x 8.0 in
Offset (ET)
45 mm
Backspacing
5.77 in
OEM tire size
235/40R18
If your S4 came with a different factory wheel or tire option, that’s fine. Trims and packages can vary. Use your owner’s manual or the driver-door label to confirm your original size, set that as the baseline in the calculator, and compare from there.
4. Implications
Here’s the working mental model. Offset and width shift where the wheel sits in the arch. Lower ET pushes the wheel outward. Higher ET pulls it inward. A wider wheel adds equally to both sides around the mounting face. That affects fender poke and inner clearance to struts, liners, and control arms.
Center bore needs attention. Your hub is 66.6 mm. A donor wheel with a larger center bore can fit, but you’ll want hub-centric rings to keep things vibration-free. A smaller center bore won’t seat without machining.
Lug bolts must match the thread size and seat style of the wheel. Your car uses M14x1.5 threads. The seat type depends on the wheel design, so match the wheel’s seat profile. If you change to thicker wheel pads or add spacers, you may need longer bolts to maintain safe thread engagement.
Tire diameter changes influence speedometer, ABS behavior, and clearance. As a rule of thumb, keep overall diameter changes modest. The calculator shows the impact instantly, which helps you steer clear of rubbing and calibration issues.
Brake caliper clearance is partly about spoke shape. Two wheels with the same numbers can behave differently. That’s why a physical test fit, or a known template, is worth doing before mounting tires.
5. Quick tests
Calculator sanity check: Set “Installed on” to 2008 S4 with the OEM baseline above. Compare any donor wheel, or plug in a custom wheel width and offset. Watch inner clearance, outer poke, and tire diameter changes before you buy.
Centering check: If a donor wheel’s center bore is larger than 66.6 mm, plan on hub-centric rings sized 66.6 mm to the wheel bore. This keeps highway vibrations in check.
Lug engagement: After a hand install, confirm solid thread engagement for each M14x1.5 bolt. If you used spacers or thick wheel pads, verify bolt length is still adequate.
Lock-to-lock clearance: With the car on the ground, turn the steering from lock to lock. Listen and look for liner contact, especially with wider wheels or wider tires.
Compression check: Drive over a speed bump at low speed or load the suspension in a driveway dip. Look for fender or liner contact at the outer edge.
Brake clearance: Spin the wheel by hand and check spoke-to-caliper spacing. Paper or clay can help reveal tight spots.
Using the Wheel Interchange Calculator
The calculator lets you compare “Wheels from (donor vehicle)” versus “Installed on (your vehicle).” For custom setups, adjust rim diameter, width, and offset, plus tire section width and aspect ratio. When you change rim diameter, the tool updates tire diameter in the comparison so you can keep things balanced.
Start with the OEM baseline above as your “Installed on” reference.
Enter a donor wheel or use “Custom wheel size” to try a new width and offset.
Watch inner clearance and outer position. That’s your quick mental model for rub risk.
Adjust tire size to keep the overall diameter near stock for a calmer speedometer and ABS feel.
Example change, just to visualize
Say you are comparing 18x8.5 ET35 to the OEM 18x8.0 ET45. Width grows by 0.5 inch, which adds about 6.35 mm to both inner and outer halves. The offset drops by 10 mm, pushing the wheel outward by 10 mm. Net result is roughly 16 mm more outer poke and about 4 mm more inner clearance. That might look great, but still confirm brake clearance and fender room on your car.
Safety-first notes
Torque your lug bolts in a star pattern using the torque value from your owner’s manual. Recheck after a short drive.
If you use spacers, pick hub-centric spacers sized to 66.6 mm with proper lip support. Longer, matching-seat lug bolts are often required.
If any OEM spec on your car is different from the table, set the calculator to your exact baseline before comparing.
The 2008 S4’s baseline is 18x8.0 ET45 with 235/40R18, 5x112, and a 66.6 mm hub. Use that as your mental model in the calculator. Confirm center bore support, offset and width changes, tire diameter, and bolt engagement. Do a quick on-car test for clearance. That set of checks turns guesswork into confidence.
Methodology and sources
Wheel interchange depends on more than bolt pattern. Where data is available, this site compares recorded OEM values:
Bolt pattern / PCD
Center bore direction (donor wheel bore must not be smaller than the hub)
Wheel diameter, width, and offset against known OEM ranges
A normal wheel spacer does not change bolt pattern. Hub rings cannot enlarge a wheel bore that is smaller than the hub. Brake clearance and tire package fitment still require vehicle-specific checks when not confirmed in the dataset.
