The four labels you will see on classic car parts are NOS, OEM, reproduction and used, and each is a trade-off between originality, price and certainty of fit. Here is what each one means and when to choose it.
The quick comparison
| Type | What it is | Best for | Watch out for |
|---|---|---|---|
| NOS (new old stock) | Original parts made years ago and never fitted | Concours-level restorations | Price, scarcity, and rubber or seals that have aged on the shelf |
| OEM (original equipment manufacturer) | Parts made by or for the carmaker to its specification | Reliable fit on newer cars and Mopar-branded items | Not always available for older models |
| Reproduction | New parts made as copies of the originals | Restorations where the original is no longer made | Quality varies between makers; check the detail |
| Used | Original parts taken from another vehicle | Hard-to-find items and budget repairs | Wear, hidden damage and an unknown history |
NOS: new, but old
NOS parts are genuine and unused, so they are the closest you can get to factory originality. The catch is age. Rubber, gaskets and some electrical parts can deteriorate even when unused, so inspect before you fit.
OEM: the carmaker’s own specification
OEM parts are made to the manufacturer’s design. For Chrysler-group vehicles that usually means Mopar. They are the least risky option for fit, which is why they are popular on newer Dodge, Ram and Jeep vehicles.
Reproduction: new copies
When the original is no longer made, reproduction parts keep classics on the road. Good ones match the originals closely; poor ones may not fit or finish the same. Buy from a supplier who stands behind the part and can tell you who makes it.
Used: the original, with miles on it
A used original can be the best answer for trim, castings or anything no longer made. Ask about condition and check for cracks, wear and corrosion.
How to choose
- Is the car a showpiece or a driver? Showpieces favour NOS or used originals; drivers can use reproduction or modern equivalents.
- Is it a safety part? For brakes, steering and suspension, favour new parts from a trusted source over unknown used ones.
- Is it wear or one-off? Wear items such as filters, pads and hoses are sensible new buys; trim and castings are often better as originals.
- What is your budget? NOS is usually the dearest, and used the cheapest, with reproduction and OEM in between.
Not sure which you need?
Send us the make, model, year and, if you have it, the VIN through Source a part, or check your VIN first. For how parts changed over the years, see old versus modern car parts.
FAQ
Is NOS better than reproduction?
NOS is original, but age can affect it, and a well-made reproduction may be the better working part. It depends on your goal.
Are used parts safe?
For non-critical parts, often yes if inspected. For safety-critical parts, buy new from a trusted source.
Need a hand at the workshop end? Oldcott Motors offers mechanical repairs and servicing and will fit parts you supply.