How to verify a Porsche
A Porsche’s story is only as good as the documents behind it. These guides show which record answers which question, and where claims usually outrun the paperwork.
Start with the number stamped on the car. The decoder marks what it proves and what only a factory record can.
Open the VIN decoder- Factory Porsche slant nose vs conversion: how to tell them apart How to tell a factory Porsche 930 slant nose from a conversion: M505/M506 codes, why pre-1987 cars may lack Kardex records, and inspection checks.
- Porsche 901 transmission: types, years and gear codes explained The Porsche 901 transmission explained: the dogleg transaxle used in 911 and 912 from 1965 to 1971, its 901/902 type numbers, gear letter codes and what replaced it.
- Porsche 911T: specs, model years and how to identify one The Porsche 911T explained year by year: 2.0, 2.2 and 2.4-litre engines, T vs E vs S, Karmann-built coupés, chassis number formats and what to check before buying.
- Porsche Certificate of Authenticity: what replaced it and how to order The Porsche Certificate of Authenticity is now the Porsche Production Specification ($150). How it compares with the Classic Technical Certificate and Kardex.
- Porsche engine numbers: decoding classic 911 engine types and serials How to read a classic Porsche 911 engine: where the number is stamped, what serial digits mean, engine type numbers 1965–1989 and matching numbers.
- Porsche M491: the Turbo Look 911 Carrera 3.2 explained Porsche option M491 explained: the 1984–1989 911 Carrera 3.2 Turbo Look, what it included, production figures, UK Supersport, and how to verify one.
- Porsche option codes: how M-codes work and what classic codes mean Porsche M-codes explained: what Mehrausstattung means, where option codes appear, why codes change between generations, and a list of classic 911 and 930 codes.
- Porsche research sources: registries, archives and books Where to research a Porsche’s history: factory documentation services, registries, club archives, and the reference books specialists cite.
- Porsche type numbers: the type list explained, from Type 7 to 992 What Porsche type numbers mean, why the list starts at Type 7, why the 911’s successor to the 356 was numbered 901, and a table of key types from 1931 to today.
- The $21 million Porsche “911 T prototype”: claim versus record The eBay Porsche listed as a lost “911 T prototype” for $21 million, checked field by field: chassis 9111120162, the Certificate of Authenticity and the slant nose.