2018 Audi S6 wheel fitment and interchange guide | wheelinterchange.com

Factory specs you can trust

tl;dr

• Match 5x112, and a 66.5 mm hub. M14x1.5 hardware.
• Use the calculator to compare donor wheels to your S6.
• Keep overall tire diameter close to stock for clean fit.
• Offset and width changes affect inner and outer clearance.
• Confirm brake caliper clearance before buying or mounting.

Recommendation

Plan the target setup

Decide if you want looks, grip, or comfort first. Use the on-page calculator to keep overall tire diameter near stock. That helps speedometer accuracy and fender clearance.

Confirm core compatibility

• Bolt pattern must be 5x112. Do not force-fit adapters.
• Center bore must seat on 66.5 mm. A larger wheel bore needs hub-centric rings. A smaller bore will not fit without machining.
• Thread size is M14x1.5. Match the seat style to the wheel design. Audi OEM typically uses bolts, not studs.

Evaluate width and offset

Enter the donor wheel size in the calculator. Then enter your current S6 setup. Watch inner clearance to the strut and knuckle. Watch outer poke relative to the fender edge. Small offset changes move the wheel a lot on this chassis. Treat the calculator’s inner and outer change values as your guardrails.

Check brake and spoke clearance

The S6 has large factory brakes. Ask the wheel maker for a brake template or test-fit bare wheels. Spoke design can make or break caliper clearance even if width and offset look fine on paper.

Select tires to match the wheel

Use the custom tire size fields in the calculator. Keep overall diameter close to the stock 255/40R19 value. Verify section width clearance on both the inner and outer sides. More width is not always faster if it rubs under load.

Hardware and accessories

• Use M14x1.5 bolts with the correct seat type for your wheel.
• If using spacers, they must be 5x112 and hub-centric to 66.5 mm. Confirm bolt length and thread engagement.
• Use hub-centric rings if the wheel bore is larger than 66.5 mm.

Impact

• Tire diameter changes affect speedometer, gearing feel, and fender gap.
• Offset changes affect scrub radius, steering feel, and bearing load.
• Wheel width changes inner clearance and outer poke under compression.
• Center bore mismatch causes vibration unless corrected with proper rings.
• Heavier wheels increase unsprung mass and can lengthen stopping distances.

Risks

• Rubbing under compression or steering lock if diameter or width grows too much.
• Caliper contact from concave faces or tight spoke barrels.
• Vibration from off-center mounting if hub-centricity is not maintained.
• Hardware mismatch. Wrong seat type or bolt length can loosen or damage hubs.
• TPMS behavior varies by trim and market. Sensors or reset procedures may differ. Confirm with your owner’s manual or dealer.

Next actions

Checklist

• Open the calculator. Set Wheels from to your donor or custom size.
• Set Installed on to 2018 Audi S6 with the factory size above.
• Tune width and offset until inner and outer clearance changes look reasonable.
• Adjust tire size to keep overall diameter near stock.
• Confirm center bore is 66.5 mm or plan for proper hub rings.
• Verify M14x1.5 bolt seat style and length with the wheel supplier.
• Request a brake template or perform a clean test-fit before mounting tires.
• After install, road test, then re-check torque and clearances.

Helpful tools

• 1/2 inch torque wrench
• M14x1.5 lug bolts
• 66.5 hub-centric rings
• 5x112 hub-centric spacers 66.5

Gotchas

• Some aftermarket wheels list 66.6 mm bores. Verify ring sizing with the seller.
• Backspacing and offset are two views of the same geometry. Use both in the calculator to sanity-check results.
• Do not rely on generic lug torque charts. Follow your Audi documentation.
• If the wheel maker cannot prove brake clearance, do not assume it will fit.

If any values above vary by trim for your S6, confirm with the on-page calculator presets and your OEM sources. When in doubt, measure on the car and get confirmation in writing from the wheel supplier.