2019 Audi TT Wheel Interchange

OEM wheel/tire sizes and fitment specs for the 2019 Audi TT.

2019 Audi TT Wheel Fitment Guide

If you are comparing wheels for a 2019 Audi TT, think of this page as a mental model you can lean on. The on-page calculator lets you compare a donor wheel and tire to your TT, then tweak custom sizes and see clearance changes in real time. The specs below are the known factory setup we have on record for this model year. Trims can vary, so use the calculator and verify against OEM sources when in doubt.

Quick recap of known OEM fitment

Bolt pattern5x112
Center bore57.1 mm
Thread sizeM14 x 1.5
Rim size18 x 8.5 in
Offset (ET)50 mm
Backspacing6.22 in
Tire size245/40R18

Note: Different trims or option packages may use different wheels or brakes. If your TT is a performance variant, confirm the factory sizes and brake clearances by VIN or an OEM parts catalog, then mirror those in the calculator.

Misconception

Any 5x112 wheel will fit a 2019 Audi TT as long as it bolts on.

Why it seems true

The bolt pattern matches, the hub looks close, and the tire fits the fender at a glance. Many vendors list broad 5x112 compatibility, which can feel convincing.

What is true

Fitment depends on more than bolt pattern. Center bore, offset, backspacing, and spoke profile affect clearance at the hub, caliper, strut, and fender. The calculator shows inner and outer movements as you change width and offset. A 1 mm offset change moves the wheel roughly 1 mm in or out. Width changes split roughly 50-50 to each side if offset stays the same.

Implications

If the hub bore is larger than 57.1 mm, the wheel can sit off-center without the right hub-centric rings. If offset is too low, the tire may poke and contact the fender lip. If offset is too high, the inner barrel can touch the strut or liner. Larger factory brakes on some trims need specific spoke shapes or spacers to clear. Tire overall diameter changes can affect speedometer readings and rubbing at full lock.

Quick tests

  • In the calculator, set “Installed on” to 2019 TT with the OEM 18x8.5 ET50, 245/40R18 baseline. Then enter the donor wheel and tire. Watch inner clearance and outer poke deltas.
  • Use this rule of thumb: each 5 mm offset change shifts the wheel about 5 mm. Half of any width change adds to the inner side, half to the outer, if offset is unchanged.
  • Check hub fit: wheel center bore should seat snugly on 57.1 mm. If larger, plan hub-centric rings sized to your wheel’s bore.
  • Plan for caliper clearance: use a straightedge across the mounting pad and measure to spokes. Compare to your caliper’s highest point.
  • Keep some safety margin for heat and flex. If the calculator shows very tight inner clearance, test-fit and inspect at full lock and over bumps.

How to use the calculator with a clear mental model

Start with the OEM baseline above. That gives you a trusted reference. Enter a donor wheel and tire, or use “Custom wheel size” and “Custom tire size.” When you change rim diameter, the tire diameter in the comparison updates so you can see the effect on fender gap and speedometer.

Think of offset as where the wheel face sits on a front‑to‑back line. Higher ET tucks the wheel in. Lower ET pushes it outward. Backspacing ties it together by measuring from the wheel’s mounting face to the inner rim lip. If inner clearance decreases a lot, expect contact with struts, spring perches, or liners. If outer poke increases a lot, expect fender or bumper interference on compression.

Safety-first checks before buying

Confirm the seat type of your lug hardware matches the wheels. Verify thread size is M14 x 1.5 as listed. If you lack a torque spec, use your owner’s manual or an OEM service source. After installation, re-check torque after a short drive. If your TT has larger brakes, test-fit one wheel first and spin it by hand to confirm caliper clearance.

Common scenarios and what the calculator tells you

  • Wider wheels, same offset: inner and outer move out by half the added width. Watch both sides for clearance.
  • Same width, lower offset: outer poke grows by roughly the offset change. Inner clearance improves by the same amount.
  • Taller tires: overall diameter increases. Expect tighter fender clearance and small speedometer changes.
  • Aftermarket wheels with larger hub bores: plan for 57.1 mm hub-centric rings to keep the wheel centered.

Helpful tools and parts

These are common items people use during wheel swaps. Match specifics to your wheels and your TT.

If your trim is different

The specs above reflect a known 2019 Audi TT factory setup. Performance trims or appearance packages can use different widths or offsets, and brake packages can change spoke clearance needs. If you suspect a difference, pull your exact factory size from the door placard and the owner’s manual, then confirm wheel part numbers or brake sizes in an OEM catalog. Set those as your baseline in the calculator for accurate comparisons.

Final quick checks before you commit

  • Calculator shows inner and outer changes that make sense for your goals.
  • Hub bore plan is clear, either direct 57.1 mm fit or rings.
  • Hardware matches M14 x 1.5 threads and proper seat type for your wheels.
  • Test fit one corner, turn lock to lock, and bounce the suspension.
  • Torque hardware to the value in your manual and re-check after a drive.

That flow keeps things calm and predictable. If a number is unclear or varies by trim, use the calculator with your actual baseline, then confirm with OEM sources. It takes a few minutes and saves a lot of hassle.

Wheel interchange calculator

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Installed on (your vehicle)