2020 Audi A4 Wheel Interchange
2020 Audi A4 Wheel Fitment Guide
Goal
You want wheels from another vehicle to fit your 2020 Audi A4 without rubbing, vibration, or warning lights. The challenge is that trim packages vary, so you need a method to validate bolt pattern, center bore, offset, and tire diameter before you buy or install. I will walk you through the checks I use in the shop and how to confirm everything with the on-page calculator on wheelinterchange.com.
Prerequisites
Assumptions and constraints for this year and model:
- Trim packages may use different tire and wheel sizes. Use your door-jamb placard or OEM documentation for your exact baseline.
- Use hub-centric fitment on Audi for best vibration control. Adapter solutions change offset and add complexity.
- Seat type of the fastener must match the wheel. Audi OE typically uses wheel bolts, not studs.
Known OEM fitment for 2020 Audi A4
The following values are available for this model year. Some items may vary by trim. If your car shows different sizes on the door placard, use those values as your baseline, then validate with the calculator.
| Parameter | Value | Notes |
|---|---|---|
| Bolt pattern | 5x112 | 5 studs, 112 mm PCD |
| Center bore | 66.6 mm | Hub pilot size |
| Thread size | M14 x 1.5 | Wheel bolt thread |
| Wheel size | 18 x 8.0 | Known OEM package |
| Offset (ET) | 40 mm | For 18 x 8.0 wheel above |
| Backspacing | 5.57 in | For 18 x 8.0 ET40 |
| Tire size | 225/50R17 | Known OEM package on certain trims |
Note the wheel and tire values above reflect different OEM packages. Your A4 may have 17 inch or 18 inch factory equipment. Confirm your baseline on the door placard, then match it in the calculator.
Tools and references
- Owner’s manual and door-jamb placard for OEM size and torque spec
- Torque wrench, 1/2 inch drive: search on Amazon
- Wheel hanger guide pin, M14 x 1.5: search on Amazon
- Hub-centric rings for 66.6 mm hub if aftermarket wheel bore is larger: search on Amazon
- Digital caliper for measuring wheel bore and thickness: search on Amazon
Step by step
Follow this sequence to evaluate a donor wheel or a custom size for your 2020 Audi A4.
1) Establish your baseline
- Read the tire size on your door-jamb placard and your current wheel size if known. The car may have 17 inch tires like 225/50R17 or an 18 x 8.0 ET40 wheel package.
- If your exact wheel specs are unknown, use the on-page calculator to start from the known values above, then adjust to match your placard size.
2) Load the on-page calculator
- Set “Installed on (your vehicle)” to 2020 Audi A4.
- Enter your confirmed baseline wheel and tire in the “Custom wheel size” and “Custom tire size” boxes if they differ from the prefilled values.
- Remember the calculator links rim diameter to tire diameter. Increasing rim diameter will update the compared tire’s overall diameter accordingly.
3) Compare a donor wheel
- In “Wheels from (donor vehicle)”, enter the donor wheel’s diameter, width, and offset. If it is an aftermarket wheel, use the exact specs stamped on the wheel.
- Check bolt pattern against 5x112 and center bore against 66.6 mm. A larger wheel bore can be adapted with hub-centric rings. A smaller bore will not fit over the hub.
- Confirm thread size M14 x 1.5 and verify bolt seat type matches the wheel’s seat design. Do not mix ball and cone seats.
4) Assess clearance and stance
- Review inner clearance to the strut and brake components and outer “poke” relative to the fender in the calculator comparison.
- Use the offset and width sliders to bring the wheel within safe clearances. Avoid contact under compression or at full steering lock.
- Keep overall tire diameter close to OEM. A change within a small percentage range is typically recommended to help maintain speedometer and driver-assistance behavior.
5) Plan hardware and install details
- Use hub-centric rings if the wheel bore is larger than 66.6 mm. Pick the correct outer diameter for your specific wheel.
- Select the correct length and seat-style wheel bolts. Length must account for wheel pad thickness and any ring or spacer used.
- Use a wheel hanger tool during installation for safety and to protect threads.
- Tighten in a crisscross pattern to the torque specified in your owner’s manual. Recheck torque after a short drive.
Validation
- Hand-rotate the wheel
Wheel interchange calculator
Select Cars for Wheel Swap
Compare wheel compatibility between two vehicles
Wheels from (donor vehicle)
Installed on (your vehicle)
