Regular Production Option

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A Regular Production Option (RPO) is a 3-digit standardized code used by General Motors to designate vehicle options and modifications. RPO codes designate how a vehicle is built. They have been used on dealership order forms and in assembly plants since at least the 1950s (e.g., for the Corvette C1). It was originally all numeric and labeled Sales Codes; in 1970 GM switched to the alphanumeric RPO code.

Even base vehicles with few optional features have multiple RPOs, since both standard components (like engine, transmission, and paint color) and extra cost options are coded.

The complete configuration of a GM vehicle (as it exited the factory) can be described by specifying the base model and its RPO codes.{{cite book |title=How to Restore Your Chevy Truck 1973–1987 |last=Whipps |first=Kevin |page=71 |year=2018 |publisher=CarTech |isbn=978-1-61325-199-7 |url=https://books.google.com/books?id=yQ1aDwAAQBAJ&dq=%22Regular+Production+Option%22+glove&pg=PA71 |access-date=2025-05-14 |via=Google Books}} Some dealerships are willing to run a VIN and print out its RPOs (with their definitions). The records are in GMs' electronic database since at least 1990.{{cite web |url=https://decoderpo.com |title=RPO Codes Decoder |website=decoderpo.com |access-date=2025-05-14}}

Beginning as early as 1967,{{cite web |url=https://outintheshop.com/2.html |website=outintheshop.com |title=67-72 Chevy truck SPID Labels |access-date=2025-05-14}} and to all models since 1984, GM attached a Service Parts Identification (SPID) label. The label is most often located on the back of the glovebox door, on the inside of the trunk lid, or on the bottom of the spare tire cover. On some SUVs and mini-vans, the SPID label is located on one of the plastic storage covers in the rear of the vehicle.

The SPID lists, in alphanumeric order, many of the options built into a vehicle, both RPOs and the older and longer Option Model numbers{{cite web |url=https://www.67-72chevytrucks.com/vboard//showthread.php?t=282003 |website=67-72chevytrucks.com |title=SPID Picture thread |access-date=2025-05-14}}{{rs|date=May 2025}} sometimes used before 1970. These codes can be used to help select the correct replacement parts.

In 2018, the SPID was replaced by a QR code label located on the B-pillar (driver's side, between front and rear doors). While fairly complete, it does not include every RPO.