Yes, the hub is identical
Same 4x100 PCD and same 56.1 mm centre bore: wheels from Mini Coupe bolt on and centre on MG MG3 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 Mini Coupe is compared with the one from MG MG3 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.
- ✓
5.5Jx15 ET45 · 175/65R15 — Fits like the original
Compared with the original ≈6Jx15 ET45 on MG MG3: shock absorber side −6.3 mm, wheel arch side −6.3 mm, tyre diameter −2.1 % : fit it with the original tyre size of MG MG3 (185/65R15), not that of Mini Coupe.
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 MG MG3 (Ecrous - 12x1.50), 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 MG MG3 on Mini Coupe?