Pattern, OE or genuine: which part should you buy?
Genuine means made for and badged by the carmaker, OE means made by the same original supplier but sold without the car badge, and pattern means an aftermarket copy made by someone else. All three fit the same car, but they differ in fit, finish, longevity and price. For panels, lights, mirrors and anything the eye or the diagnostic port will notice, a genuine used part gives you carmaker quality at a used price. Here is what each term means, how to tell them apart and when each one is the right choice.
Genuine, OE and pattern side by side: what is the difference?
The three words are used loosely in listings, so this is the plain version. The column that matters most for a repair is fit and finish, because that is where the price difference shows up on the car.
| Type | Who makes it | Branding | Fit and finish | Typical price new |
|---|---|---|---|---|
| Genuine (OEM) | The carmaker's contracted supplier | Carmaker logo and part number | Identical to factory | Highest |
| OE / OES | The same supplier, sold under its own name | Supplier brand (Hella, Valeo, Bosch, ZF) | Same specification as genuine | Mid to high |
| Pattern (aftermarket) | An unrelated manufacturer | Own brand or none | Varies from good to poor | Lowest |
| Genuine used | The carmaker's supplier, removed from a donor car | Carmaker logo and part number | Identical to factory | Usually below pattern new |
What is a genuine part?
A genuine part is the one your car left the factory with, or its direct dealer replacement. It carries the carmaker's logo and part number, and it is sold new through the dealer network. The carmaker rarely makes it themselves; a supplier such as Hella, Valeo, Bosch or ZF builds it to the carmaker's drawing and the carmaker approves and brands it. Bought new, genuine is the most expensive option because you are paying for the dealer chain and the badge. Bought used from a broken car, it is exactly the same component for a fraction of the cost. A used genuine part has also already proved it fits, because it was bolted to the same model for years.
What does OE mean, and is it as good as genuine?
OE stands for original equipment, and OES for original equipment supplier. It is the part made by the same supplier that produces it for the carmaker, built to the same specification and often on the same production line, but sold in the supplier's own box without the car badge. The difference is usually the logo and the price. You can often spot the relationship on the part itself: a genuine Audi A6 headlight in our yard carries the Audi numbers 4G0941033J and 4G0941773J and the Hella number 1LX01187713 on the same casing. A Vauxhall Astra J headlight is listed under its Hella number 1LG01001169. Where a genuine OE supplier part exists, it is a sound buy. Just check that the supplier really is the factory one for your car, because some brands make both OE and aftermarket ranges.
What is a pattern part, and when is it fine?
Pattern parts are aftermarket copies made by companies with no link to the carmaker. They are the cheapest option new and the quality ranges from very good to poor. For a simple service item such as a filter, a wiper blade or a brake disc from a reputable brand, a pattern part is often fine. The problems arrive with anything that has to line up, seal, match or communicate. Pattern bumpers can sit proud at the wing edge, pattern headlights can fog or scatter the beam, pattern mirrors may not take the original glass or indicator, and pattern electronics may throw fault codes. If exact fit or finish matters, or the part has to pass an MOT beam test, pattern is a gamble.
How do I tell what I am looking at from the part number?
Look at the number format and the brands moulded into the part. A genuine part has the carmaker's number in the carmaker's style: Mercedes numbers start with an A and ten digits, such as A0009063322 on a B180 alternator. Ford numbers mix letters and digits in blocks, such as CV6T10300BC on a Focus alternator or CJ54S16003ADW on Kuga mirror trims. Audi and VW group numbers start with a three-character prefix such as 4G0 or 02Q. Many genuine parts also carry the supplier's own number alongside, which is how OE parts are matched. A pattern part usually has none of these, or a number in the aftermarket maker's own format. Our guide to OE part numbers explains how to use the number to confirm fitment.
So which should I buy for my repair?
For body panels, lights, mirrors, trim and anything electronic, a genuine used part is usually the smart buy: factory fit and finish, the correct part number, and a price that is often below a new pattern copy. For a one-off wearing item that will be replaced again in two years, a good pattern part may be the sensible choice. For a safety-critical component on a newer car, new genuine or OE is worth the money. The one thing to avoid is a cheap pattern copy of a part the car has to look at, line up or talk to. If you are weighing up a used part, our post on whether used car parts are safe gives the checklist.
Examples from our yard
Every one of these is a genuine used part from a known donor car, listed with the carmaker's number so you can match it against your old one. Stock changes daily, so the collections show what is live.
- Audi A6 C7 facelift full LED headlight, left, 4G0941033J (also marked 4G0941773J and Hella 1LX01187713)
- Vauxhall Astra J left headlight 1LG01001169
- Ford Focus Mk3 alternator CV6T10300BC
- Mercedes B180 W246 alternator A0009063322
- Kia Sportage 1.7 CRDi alternator 373002A850
- Jaguar XF alternator GX7310300DE
- Volkswagen group 2.0 TDI six-speed manual gearbox 02Q301103, shared across VW, Skoda, SEAT and Audi
- Ford Kuga wing mirror trim pair CJ54S16003ADW
Browse live stock in lighting and electrical and electronics, or go straight to Audi parts. If it is an alternator you are after, read how to buy a used alternator that works first.
Buy with confidence
Every part we sell is a genuine part removed from a known donor car, inspected before listing, tested where possible and photographed so you see the actual item. Tracked UK delivery on every order, free on most parts (panels, engines and gearboxes carry a charge shown on the product page), and 30 day returns. Order before 2pm on a working day for same-day dispatch. Send us your registration and the part you need and we will confirm fitment before you buy. Parts worth your trust.
Frequently asked questions
What is the difference between genuine, OE and pattern parts?
Genuine parts are made for the carmaker by its supplier and carry the carmaker's badge and part number. OE parts are the same supplier's part sold under the supplier's own brand without the car badge, to the same specification. Pattern parts are aftermarket copies from unrelated manufacturers, and their quality varies from good to poor.
Is an OE part as good as a genuine one?
Usually yes. A true OE or OES part is made by the same supplier that builds it for the carmaker, often on the same line, with only the branding and the price different. Check that the supplier is the factory one for your car, because some brands sell both OE and aftermarket ranges under the same name.
When should I avoid pattern parts?
Avoid pattern copies for anything that has to line up, seal, match or communicate: bumpers, wings, headlights, mirrors and electronics. Poor panel gaps, scattered headlight beams and fault codes are the usual complaints. For simple wearing items from a reputable brand, such as filters, wiper blades or brake discs, a pattern part is often fine.
Why buy a genuine used part instead of a new pattern part?
Because a genuine used part is the exact component your car was built with, so it fits and behaves as the factory intended, and it usually costs less than a new pattern copy. The part number on it can be matched to your old one, which removes most of the fitment risk. For panels, lights and mirrors it is the best value option.
How can I tell a genuine part from a pattern part?
Look for the carmaker's part number in the carmaker's format moulded or printed on the part, often alongside the supplier's own number. Genuine parts also carry the carmaker's logo. A pattern part usually has neither, or a number in the aftermarket maker's own style. If a listing shows no part number at all, ask before buying.