Yes, the hub is identical
Same 5x112 PCD and same 57.1 mm centre bore: wheels from Audi RS Q3 bolt on and centre on Audi R8 axe arrière without rings. You still need to check the offset and tyres, detailed below.
≈: width estimated from the original tyre size.
Wheel by wheel: offset and tyres
Each original wheel from Audi RS Q3 is compared with the one from Audi R8 axe arrière of the same diameter: how much closer the wheel gets to the shock absorber or how far it sticks out of the wheel arch, and whether the tyre keeps the same overall diameter.
- ✓
≈7Jx19 ET38 · 225/50R19 — Fits like the original
Compared with the original 11Jx19 ET50 on Audi R8 axe arrière: shock absorber side −62.8 mm, wheel arch side −38.8 mm, tyre diameter +2.7 % : fit it with the original tyre size of Audi R8 axe arrière (295/35R19), not that of Audi RS Q3.
Comparison for guidance only (estimated width). Check in detail
Before fitting the wheels
An identical hub is not enough: offset, width and diameter change the position of the wheel, and larger calipers can touch a smaller wheel. Original wheels often use bolts or nuts with a specific seat: keep the fixings intended for the wheel, with the thread of Audi R8 axe arrière (M14x1.50), tightened to the torque shown on its vehicle page. Finally, check that the size is among the approved fitments for your vehicle. This comparison is for guidance only: have the fitting approved by a professional.
And the other way round: wheels from Audi R8 axe arrière on Audi RS Q3?