Technical Service Bulletin No. 61-21 — 1991 PORSCHE 928
ENGINE AND ENGINE COOLING
Bulletin Details
| TSB ID | No. 61-21 |
| Manufacturer | |
| Vehicle | 1991 PORSCHE 928 |
| Component | ENGINE AND ENGINE COOLING |
| Communication Date |
Bulletin Summary
List of approved engine oils for all Porsche models using C40 oil.
About Technical Service Bulletins
A Technical Service Bulletin (TSB) is a document issued by a vehicle manufacturer to its dealers, describing a known issue with a specific vehicle or set of vehicles and the recommended procedure to fix it. Unlike recalls, TSBs are not mandatory and are typically only performed if an owner reports the related issue. However, TSBs can be an indicator of common problems with a vehicle.