The current Opel Manta is 4,419 mm long, 1,674 mm wide and 1,334 mm tall, on a 2,518 mm wheelbase.
| Years | Length | Width | Height | Wheelbase | Boot capacity | Turning circle |
|---|---|---|---|---|---|---|
| 1975–1982 | 4,445 | 1,670 | 1,330 | 2,518 | 380 | — |
| 1978–1982 | 4,397 | 1,670 | 1,339 | 2,518 | 330 | — |
| 1982–1989Current | 4,419 | 1,674 | 1,334 | 2,518 | 355 | 10.8 |
Exterior figures are manufacturer specifications for the Manta, averaged per generation across its variants and shown for the most common body style. Generations with the same size are merged. Boot capacity is the seats-up figure where the manufacturer quotes one.