The most common tyre size on the Alfa Romeo Junior is 215/55R18 (overall diameter ≈ 694 mm). Exact fitment depends on generation and engine — full breakdown below.
| Engine | Tyre sizes |
|---|---|
| Junior Elettrica - 143 PS - Electrical | 225/40R20 |
| Junior Elettrica - 84 PS - Electrical | 215/55R18 215/60R17 215/65R16 |
| Junior Ibrida - 136 PS - Mild-Hybrid - 1199 Hubraum | 215/55R18 215/60R17 215/65R16 |
| Junior Ibrida 4WD - 136 PS - Mild-Hybrid - 1199 Hubraum | 215/55R18 215/60R17 215/65R16 |