The most common tyre size on the Alfa Romeo Alfa 90 is 185/65R15 (overall diameter ≈ 622 mm). Exact fitment depends on generation and engine — full breakdown below.
| Engine | Tyre sizes |
|---|---|
| 90 1.8 - 116 PS - Benzin - 1767 Hubraum | 185/65R15 185/70R14 195/60R15 |
| 90 2.0 - 128 PS - Benzin - 1948 Hubraum | 185/65R15 185/70R14 195/60R15 |
| 90 2.4 TD - 110 PS - Diesel - 2325 Hubraum | 185/65R15 185/70R14 195/60R15 |
| 90 2.4 TD - 110 PS - Diesel - 2376 Hubraum | 185/65R15 185/70R14 195/60R15 |
| 90 2.5 - 150 PS - Benzin - 2464 Hubraum | 185/65R15 185/70R14 195/60R15 |