1981 - New rear bumper

Only minor external changes where made this year such as a new rear bumper that where extended along the sides to provide better protection.
New BBS Mahle rims

Standard rims for all models where 6.5 x 14 BBS Mahle, the dimension where the same but the design where new. The tire dimension was 205/70 VR tires. Optional was a set of multi-spoke rims with Michelin TRX 220/50 VR 390.
Production numbers for 1981
| Model | Units | Total for model | Total all models |
| 628 CSi | 410 | 785 | 5652 |
| 628 CSi A | 182 | ||
| 628 CSi RHD | 47 | ||
| 628 CSi A RHD | 146 | ||
| 633 CSi | 74 | 136 | |
| 633 CSi A | 62 | ||
| 633 CSi USA | 913 | 1539 | |
| 633 CSi A USA | 626 | ||
| 633 CSi A Japan | 106 | 106 | |
| 635 CSi | 1605 | 3086 | |
| 635 CSi A | 728 | ||
| 635 CSi RHD | 238 | ||
| 635 CSi A RHD | 515 |
