2021 Audi S6 Wheel Interchange

2021 Audi S6 Wheel Fitment Guide

Think of this page as a clear mental model for what fits your 2021 Audi S6 without drama. We are using the factory specs shown below, and you can sanity check anything with the on-page calculator. If your trim or package differs, that is fine. Use the calculator and your owner’s manual to confirm.

Quick OEM reference

Factory equipment can vary by package. If your build sheet shows a different wheel or tire package, plug that into the calculator first for an accurate baseline.

1) Misconception

If the donor wheel is 5x112, it should bolt right onto a 2021 S6.

2) Why it seems true

Listings and forums often lead with bolt pattern. A lot of VAG cars share 5x112, so it feels interchangeable. Many photos look fine from the outside, which hides issues you only notice on the road.

3) What is true

Fitment is a stack of clearances that all need to work at once. Bolt pattern is only one layer. On the 2021 S6, the key layers are:

• Center bore: 66.5 mm hub. The wheel needs to be hub-centric or ringed to 66.5 mm.
• Offset and width: These control inner clearance and outer poke.
• Brake caliper and spoke design: Physical shape matters as much as numbers.
• Thread size and seat style: M14 x 1.5 bolts, and the correct seat profile for the wheel.
• Tire diameter and section width: Rolling diameter and sidewall shape affect rubbing and speedo.

Our calculator mirrors this thinking. You compare a donor wheel against your S6 baseline, then adjust width, offset, and tire to see what changes. Changing rim diameter updates tire diameter in the comparison so you can keep overall height in check.

4) Implications

• Offset mental model: Lower ET pushes the wheel outward. Higher ET tucks it inward. Rule of thumb, a few millimeters can be the difference between a clean fit and a rub.
• Width tradeoffs: Wider wheels add half the extra width inward and half outward unless you offset-compensate. The calculator shows inner clearance to strut and outer poke near the fender.
• Center bore fit: If an aftermarket wheel has a larger bore than 66.5 mm, you will likely want hub-centric rings sized to 66.5 mm on the inner diameter. The wheel’s outer ring size varies by brand, so confirm before you buy.
• Brake clearance: Two wheels with the same size can differ in spoke-to-caliper clearance. Use templates if provided, or test-fit carefully.
• Hardware caution: The S6 uses M14 x 1.5 bolts. Seat style must match the wheel. Many Audi OEM wheels use a ball seat. Many aftermarket wheels use a cone seat. Mismatched seats can loosen and damage the wheel.
• Tire diameter: Keep overall diameter reasonably close to stock to maintain speedometer behavior and suspension geometry. The calculator will show percentage change to help you decide.
• Load rating: Ensure wheels and tires meet or exceed the S6’s load needs. Check the wheel’s stamped rating and your tire’s load index.

5) Quick tests

Use the on-page calculator

• Set “Installed on (your vehicle)” to 2021 Audi S6 with the OEM 20x8.5 ET43, 255/40R20 baseline shown above. If your car came with different OEM sizing, enter that first.
• Pick “Wheels from (donor vehicle)” and enter the donor specs if you know them. If not, start with “Custom wheel size”.
• Adjust width and offset. Watch two numbers: inner clearance change and outer poke change. Keep inner clearance positive with a cushion for tire bulge and suspension flex.
• Set your “Custom tire size”. If you change rim diameter, review the calculator’s total diameter change. Keep the percentage close to stock for best results.

Physical checks after a test-fit

• Hub-centric feel: With the car lifted and a wheel hanger installed, the wheel should seat snugly on the 66.5 mm hub without wobble. If the bore is larger, use the correct ring set for your wheel.
• Caliper clearance: Spin the wheel by hand. It should rotate freely with a couple millimeters of spoke clearance. Check both front and rear.
• Fender and liner sweep: With the car on the ground, turn from lock to lock. Load the suspension with a gentle bounce. Listen and feel for contact.
• Road shakedown: Short drive, then re-check torque with a calibrated wrench. Re-torque after some miles as a rule of thumb.

Safety and hardware notes

• Torque to the spec in your 2021 S6 manual. Tighten in a star pattern on a cool wheel.
• Use the correct seat style bolts that match the wheel design, M14 x 1.5 threads.
• If using rings, confirm inner diameter is 66.5 mm and the outer diameter matches your wheel’s bore. Materials vary. Heat resistant options tend to stay put better.
• Monitor tire load index and speed rating that meet your S6’s requirements.

Common “what if” scenarios

• I want a wider wheel: Try +0.5 to +1.0 inch in the calculator. Offset may need to change to keep inner clearance safe. Use the inner clearance readout as your guide.
• I want more concavity: That often means lower ET. Check fender poke and caliper clearance carefully. Concave designs can run tighter at the spokes.
• I want smaller diameter for winter: Enter a smaller rim and a taller tire that keeps overall diameter near stock. The calculator will adjust tire diameter in the comparison so you can track the delta.

Tool picks that make life easier

• 1/2 inch torque wrench for accurate, repeatable bolt torque.
• Wheel hanger tool M14 to support heavy wheels on the hub.
• M14x1.5 ball seat lug bolts or search your wheel’s exact seat style. Verify seat type before buying.

Quick recap

It is easy to think 5x112 is the whole story. It feels right because so many cars share that pattern. What actually fits your 2021 Audi S6 depends on offset, width, center bore, brake shape, hardware, and tire diameter. The upside is control. With the calculator and a cautious test-fit, you can dial in a setup that looks right and drives clean, without guessing.