2017 Audi TT Wheel Interchange

OEM wheel/tire sizes and fitment specs for the 2017 Audi TT.

2017 Audi TT Wheel Fitment Guide

You want correct fitment without surprises. I respect that. I manage wheel risk for a living, so I’ll walk you through the edges first, then bring it back to calm. We will use what is known, confirm what may vary, and lean on the on-page calculator when needed.

1. Baseline

These are the known factory fitment details for the 2017 Audi TT. Trims and regions can vary in some cases. If your car differs, confirm by VIN with OEM sources and double check against the calculator.

SpecValue
Bolt pattern5x112
Center bore57.1 mm
Thread sizeM14 x 1.5
OE rim diameter18 in
OE rim width8.5 in
OE offset (ET)50 mm
OE backspacing6.22 in
OE tire size245/40R18

If any value on your car seems different, treat it as a flag. Pull the owner’s manual, inspect the back of the wheel, or verify with a dealer parts advisor using your VIN. The calculator on this page is built for these checks.

2. Edge cases

Most swaps go fine when you stay close to stock. Problems sneak in at the edges. Here is where I see risk on this model.

Offset and width changes can push the wheel too far out or in. Too much poke can contact the fender lip on compression. Too much inner shift can touch the strut or liner at full lock. Spoke shape also matters. A wheel may clear in diameter yet still kiss a big caliper face.

Center bore is 57.1 mm. Aftermarket wheels often come larger. That can be fine with the correct hub centric ring. Without a ring, you may get vibration that balancing will not fix.

Hardware uses M14 x 1.5 threads. Seat style can differ by wheel brand. Ball seat and cone seat parts do not interchange safely. Mixing seats can loosen under load.

Tire fit on wheel width matters. A narrow tire on a wide rim can stretch the sidewall. A wide tire on a narrow rim can “balloon.” Both can change real clearance and steering feel. Also watch overall tire diameter. Speed and ABS systems may get touchy with bigger changes.

Spacers can solve caliper contact in some cases. They also change effective offset and require longer hardware. Poorly sized spacers can reduce thread engagement and load the hub face.

3. Detection

Use the calculator before you buy. It compares “Wheels from (donor vehicle)” versus “Installed on (your vehicle).” You can set a custom wheel size and a custom tire size. When you change rim diameter, the tool updates tire diameter in the comparison. That lets you preview clearance changes in millimeters and inches.

Model your current setup as baseline. Enter the OE 18x8.5 ET50 with 245/40R18. Then try your target width and offset. Watch two numbers closely. Outer position, which affects fender poke. Inner position, which affects strut and liner clearance. Keep a reasonable margin in both directions. If the numbers look tight, assume real-world deflection may erase a few millimeters.

On-car checks are simple. Dry fit one wheel without a tire first if possible. Spin by hand. Turn lock to lock. Compress the suspension with a jack under the control arm. Look for witness marks on liners and calipers. Count thread engagement on each lug bolt. You want solid engagement across the full thread, not just the tip. Confirm the wheel sits flat on the hub, not hung up on the bolt heads or a burr.

Measure the hub. A basic caliper can verify the 57.1 mm bore and ring fit. A straight edge across the wheel barrel can help you estimate backspacing relative to calipers and knuckles.

4. Mitigations

Use hub-centric rings when the wheel center bore is larger than 57.1 mm. Rings center the wheel and reduce vibration. Choose the outer size to match your wheel’s bore. The inner size must be 57.1 mm.

Match seat style on hardware. If your wheel requires ball seat, use ball seat M14 x 1.5 bolts. If it requires cone seat, use cone seat M14 x 1.5 bolts. When spacers are used, extend hardware length accordingly. Do not stack thin spacers. Use quality hub-centric spacers if needed.

Keep overall tire diameter close to stock when possible. Small changes may be manageable, but large jumps can affect speed indication and gearing feel. Use the calculator to watch overall diameter and sidewall height as you test sizes.

When caliper clearance is the concern, consider spoke design first. A wheel with more face clearance may solve it without a spacer. If a spacer is the only path, test the minimum thickness that clears under load and re-check thread engagement.

Torque fasteners to the value in your owner’s manual. Re-torque after the first short drive. Heat cycles can relax a fresh interface.

5. Safe defaults

Stay near the OE 18x8.5 ET50 baseline when you want low risk. A modest width change and a small offset change can work in many cases, especially on stock brakes and stock ride height. Keep overall tire diameter close to stock for the smoothest experience. Use hub-centric rings any time the wheel bore is larger than 57.1 mm. Use M14 x 1.5 hardware with the correct seat style for your wheel. When in doubt, test a single corner and inspect before committing.

6. Checklist

  • Confirm your car’s specs by VIN and manual. Note 5x112, 57.1 mm bore, M14 x 1.5 threads.
  • Set the calculator to OE 18x8.5 ET50 with 245/40R18 as baseline.
  • Test your target wheel width and offset. Review inner and outer position changes.
  • Keep tire diameter close to stock. Verify section width fits the wheel maker’s allowed range.
  • Plan hub-centric rings if wheel bore exceeds 57.1 mm.
  • Match hardware seat style. Verify full thread engagement, especially

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