Automotive part numbers, and Porsche pieces in particular, aren’t the easiest things to decipher. There are, however, a few tricks that will help you out. First off, early 356 part numbers are split into the following sequence: three digits, three digits and two digits (xxx xxx xx), for a total of eight numbers. Later Porsches have 11 digits, split into three digits, three digits, three digits and two digits (xxx xxx xxx xx).
The prefix: the model
We’ll talk mostly about the later style, as it is by far the most common situation we run across. Most Porsche parts use a 3-digit prefix that relates them to a specific model in the Porsche range, usually the one they were first designed for. However, Porsche has been known to carry these parts on to later models (e.g. 914 emergency brake switches are also used as 968 door light switches).
- Standard model prefixes include 901, 902, 911, 930, 914, 928, 964, 986, 996, etc., which usually correlate to the model on which you will find them.
- 999, 900 or N prefixes generally denote hardware components with multiple uses.
- As the 914-4 used a Volkswagen derived “type 4” engine, there are many VW part numbers used: 022, 021 and 113 are common prefixes for these parts.
- The 924 / 944 / 968 trio of cars was originally developed as a new Volkswagen sports car using existing components, such as the Audi 2.0 liter engine, the VW MK1 derived front suspension and the VW Super Beetle derived rear suspension. As such, many of these components use VW part numbers.
- The automatic transmission found in the 928 was developed with Mercedes-Benz and uses their part numbering system, with prefixes like 115, 126 and 722 to show for it.
- Transmission or engine parts can often receive their own prefix based on the number of that engineering exercise: 915, 741, 547, 950, etc.
The second group: the system
Moving on, we get to the meat of the part number. The first number in this second series of three digits signifies the section / system of the Porsche where the part can be found (i.e. engine, transmission, front suspension, rear suspension, etc.). The final two numbers in the series are related to the diagram number, within Porsche’s PET system, on which they can be found (PET is the internal system of diagrams used for seeking out an individual part, most often found at dealership parts counters). After some digging, this seems to be based more on coincidence than actual fact, but it seems that as the second and third digits increase in value, the part is found deeper in numerically higher diagrams. The outline below shows which numbers correlate to which system, with a few of the components that can be found there.
| Group | System | Typical components |
|---|---|---|
| 100 | Engine | Rotating assembly, flywheel, case and cylinder head related components |
| 200 | Fuel and exhaust | Fuel tanks, pumps, lines, regulators; mufflers, manifolds, gaskets, tips, turbochargers |
| 300 | Transmission | Clutches, pressure plates, T/O bearings, internal components, mounts, clutch slave cylinders |
| 400 | Front axle / steering | Front wheel bearings, wheel seals, uprights, hubs, lug studs, suspension components; steering wheel, steering rack components, column mounted switches |
| 500 | Rear axle | Drive axles, rear wheel bearings, trailing arms, hubs, lug studs |
| 600 | Wheels / brakes | Wheels, center caps, spacers, lug nuts, master cylinder, calipers, pads, rotors |
| 700 | Levers / pedals | Accelerator, clutch and brake pedal assembly, accelerator and clutch cables, clutch master cylinders; hood, trunk, fuel door and engine cover release cables; transmission control levers and linkages |
| 800 | Body | Sheet metal, trim, emblems, decals, interior components from upholstery to hardware, all HVAC components |
| 900 | Electrical | Engine ignition system (distributor, coil, plugs and wires), alternators, starters, windshield wiper and washer system, ignition and dash switches, electric motors, in-car entertainment, lighting |
The third group: the part
The third set of digits is an internal code for the “actual number of the part.” This does not seem to have any significance to the end user; perhaps it is based upon the engineering project number for that specific piece.
The last two digits: the modification
The final pair of digits is known as the “modification number.” For the most part, Porsche parts end in a pair of zeros when they’re first designed or released. As parts become superseded, the 00 is replaced with 01, 02 and so on. Sometimes the two digits denote the finish or the material the part is made out of. They can even stand for the body type the part works on: 41 is typically used for cabriolet-specific parts.
