2021 Audi S4 Wheel Interchange

2021 Audi S4 Wheel Fitment Guide | wheelinterchange.com

Known OEM Fitment For 2021 Audi S4

The values below reflect known factory specifications for the 2021 Audi S4. Trims and regional packages can vary. Always confirm against your VIN, the driver-door placard, the owner’s manual, and by using the on-page calculator.

Notes:

• Fasteners are M14 x 1.5 wheel bolts. Seat type and bolt length depend on the wheel. Match the wheel manufacturer’s requirement.
• If your vehicle’s label or catalog differs, use those OEM sources first and use the calculator to verify differences.

How To Use The Wheel Interchange Calculator

The calculator compares a donor wheel and tire setup to what will be installed on your 2021 Audi S4. It updates tire diameter automatically when you change rim diameter so you can predict clearance, poke, speedometer change, and more.

• Select Wheels from (donor vehicle). Enter or select the wheel and tire specs you want to try. If you only know the wheel size, use the Custom wheel size fields and pick a reasonable tire size to match.
• Under Installed on (your vehicle) choose 2021 Audi S4, then verify the baseline OEM spec matches your door placard. Edit if your trim is different.
• Use Custom wheel size to try new rim diameter, width, and offset. The tool will show inner clearance change to the strut and outer poke toward the fender.
• Use Custom tire size to change section width and aspect ratio. The calculator will update overall tire diameter and speedometer error.
• Review results. Aim to keep overall diameter change small, keep inner clearance safe, and avoid excessive poke that could contact the fender or liner.
• If you plan spacers, add their thickness to the offset calculation by reducing ET by the spacer thickness. Example: a 10 mm spacer on ET40 acts like ET30.

Fitment Checklist Before You Buy

• Hub size and centering. The Audi hub bore is 66.5 mm. If an aftermarket wheel has a larger center bore, use 66.5 mm hub-centric rings sized to the wheel’s bore. Do not use wheels with a smaller bore than 66.5 mm.
• Bolt pattern and fasteners. Must be 5x112 with M14 x 1.5 bolts. Match seat type to the wheel design. Confirm bolt length especially if using spacers.
• Offset and clearance. Use the calculator to confirm both inner clearance to the strut/spring and outer poke to the fender. Large changes in offset or width can cause rubbing or bearing load issues.
• Tire overall diameter. Keep total diameter close to stock to maintain ABS, traction control, and speedometer accuracy. Many installers target within about 3 percent, but verify what your shop or OEM recommends.
• Brake caliper clearance. The S4 has large brakes. Obtain a brake template from the wheel manufacturer when possible and test-fit before mounting tires.
• Load rating. Wheel and tire load ratings must meet or exceed the values on your door placard.
• TPMS. Some vehicles use direct sensors inside the wheel while others use indirect systems. Check your owner’s manual to determine if new sensors, coding, or relearn is required.
• Spacers and rings. Only use hub-centric spacers. Ensure remaining hub lip engagement and use appropriately longer M14 x 1.5 bolts if required.
• Alignment. After any significant change in wheel width or offset, have the alignment checked.

Plus Sizing And Common Upgrades

Many owners move to larger diameter wheels for summer performance or downsize for winter tires. The safe approach is to model changes in the calculator and verify all clearances on the car.

• Plus sizing method. Increase wheel diameter in 1 inch steps and reduce tire aspect ratio to keep overall diameter similar. Use the calculator to keep diameter change small.
• Width changes. A wider wheel and tire increase lateral grip but reduce inner clearance and increase outer poke. Check both sides with the calculator and with a physical test-fit.
• Offset tuning. Small offset changes shift the wheel in or out. Larger changes can affect steering feel and bearing loads. Keep changes modest unless you have measured clearances carefully.
• AWD considerations. Maintain very similar rolling circumference on all four tires. Mismatched diameters can stress the drivetrain. Consult your owner’s manual for rotation and replacement guidance.
• Winter setups. Narrower tires can improve snow traction. Ensure brake clearance and overall diameter remain appropriate.

If your trim or brake package differs from the baseline values above, confirm your exact OEM spec before choosing an upgrade. Use OEM documentation and the calculator to verify.

Installation Tips

• Test fit a bare wheel first. Spin by hand to ensure caliper and suspension clearance before mounting tires.
• Clean the hub face and center bore. Remove rust and debris so the wheel seats flush. Use dry, clean mating surfaces unless your OEM specifies otherwise.
• Hub-centric rings. If required, install rings snugly in the wheel and confirm the wheel centers on the 66.5 mm hub.
• Support the wheel during installation. A wheel hanger guide pin for M14 x 1.5 helps align the wheel and prevent thread damage.
• Torque correctly. Hand start all bolts, snug in a star pattern, then torque in stages to the value in your owner’s manual or service information for your VIN. Re-check torque after 50 to 100 miles.
• Spacers. Use hub-centric spacers only. Verify hub lip engagement and use appropriately longer bolts. Re-torque after initial miles.
• TPMS. If using direct sensors, install new seals as needed and perform relearn or coding per the service manual.

Tools And Helpful Supplies

• 1/2 inch drive torque wrench
• Wheel hanger guide pin M14 x 1.5
• 66.5 mm hub-centric rings sized to your wheel bore
• 1/2 inch breaker bar

Also useful: floor jack, jack stands, wire brush for hub cleaning, anti-seize only if specified by OEM, gloves, and a valve core tool if servicing TPMS.

FAQs

• Will 19 inch wheels fit my 2021 Audi S4?

  They can in many cases, but fitment depends on wheel width, offset, tire size, and brake clearance. Use the calculator to model a 19 inch setup, verify inner and outer clearances, and confirm with the wheel manufacturer’s brake template. Check against your OEM specs and test-fit before mounting tires.

• What spacer size can I run safely?

  Spacer thickness depends on your current offset and clearance goals. Model the effect by subtracting spacer thickness from wheel offset in the calculator. Ensure the spacer is hub-centric and that you have sufficient hub lip engagement and appropriately longer M14 x 1.5 bolts. Inspect fender and liner clearance with the car at ride height and under compression.

• Do I need hub-centric rings on aftermarket wheels?

  If the wheel’s center bore is larger than 66.5 mm, use rings sized 66.5 mm to the wheel’s bore to center the wheel on the hub. If the wheel bore is exactly 66.5 mm, rings are not required. Do not use wheels with a bore smaller than 66.5 mm.

• Which lug bolts should I use with new wheels?

  Use M14 x 1.5 bolts as specified, but match seat type and required length to the wheel and any spacer. The wheel manufacturer will specify ball or cone seat and the required shank length. Ensure adequate thread engagement as specified by the fastener and wheel manufacturer.

• What is the correct torque for the wheel bolts?

  Refer to your owner’s manual or Audi service documentation for the torque specification for your exact VIN. Torque in a star pattern in stages and re-check after 50 to 100 miles.

• Does the 2021 S4 need TPMS sensors in the wheels?

  Systems vary by market and trim. Some vehicles use direct in-wheel sensors while others use an indirect system that monitors wheel speed. Check your owner’s manual to confirm whether sensors are required for your vehicle and how to perform relearn or coding.

• Is a staggered setup OK on an AWD Audi?

  Audi AWD systems require closely matched rolling circumference front to rear. If using different widths or diameters, ensure rolling diameters remain essentially equal and follow Audi guidance to avoid drivetrain stress. When in doubt, use a square setup with identical sizes and rotate regularly.

Always validate final selections with OEM documentation and a professional test-fit. Use the Wheel Interchange calculator on wheelinterchange.com to compare any donor setup against your 2021 Audi S4 before you buy.