Genuine, aftermarket, used: what the parts labels mean

Anyone looking for a water pump, a control arm or a set of brake pads meets the same part in several versions: in the carmaker's box, in the supplier's box, from an independent manufacturer, as a remanufactured exchange unit and as a used part from a dismantled car. The price range between them is wide, and the labels meant to explain it are not uniformly protected.

Three questions sort the field better than any label: who made the part? To whose drawing and test specification? And who answers for it if it fails early — the carmaker, the parts maker or only the dealer who sold it? The answers differ by tier, and they matter more than the colour of the box.

A genuine part is what the carmaker sells through its network under its own name and part number. In many cases it did not make the part itself; a supplier did, the same one that delivers it to the assembly line. But the carmaker owns the specification, tests the series and puts its name to it.

The premium pays for that responsibility, for the logistics of a worldwide network and for the certainty that the part fits the chassis number it was ordered for. It makes most sense where a warranty or a goodwill decision is at stake, for parts that interact with software, and for components that simply have no equivalent alternative.

Many suppliers also sell the parts they make for original equipment under their own name in the independent trade. Technically it is often the same part from the same line, sometimes without the carmaker's logo, which was removed afterwards or never applied. For wear parts this is the tier with the most honest ratio of price to value.

Care is needed with the wording. “OE quality” is a claim about standard, not about origin, and not everyone who uses it supplies a carmaker at all. What holds is a parts maker that lists the carmaker's OE number against its article and is known as a supplier of that part — not the phrase on the packaging.

Aftermarket parts come from manufacturers who make the part to their own drawing so that it takes the place of the original. The range runs from companies that beat the original in their niche to goods where only the dimensions are right. Price alone does not reliably separate the two.

For some safety-relevant replacement parts the European rules require an approval that shows on the part or its packaging — for brake pads and discs, for example, approval under UN ECE Regulation 90, and for headlamps and lights an approval mark. Where such a marking is required and missing, that is not a detail but a reason not to fit the part.

For parts without such a requirement, the maker's reputation remains the best guide: how long has it been on the market, does it also supply workshop chains, does it publish cross-reference numbers and dimensions openly? A workshop that fits parts every day usually knows exactly which brands come back.

An exchange unit is a used component that has been industrially stripped, tested, fitted with new wear parts and reassembled. It is common for starter motors, alternators, turbochargers, injection components, brake calipers and gearboxes — assemblies whose housings and main bodies last a long time while individual internals wear.

An exchange unit nearly always comes with a core charge: the price applies on condition that the removed part comes back, and in a state that can be remanufactured. A cracked housing or a missing attachment can cost you the deposit. Read the conditions before you throw away or strip the old part.

On Carvexia the condition of a part is shown on the listing: new, remanufactured or used. The information comes from the seller — what a remanufactured unit includes with that seller, what warranty they give and how the core charge works is set out in their terms.

A used part comes from a car that has been dismantled and is sold as it came out, at best cleaned and tested. Its strength lies where new parts are expensive, hard to get or no better anyway: body panels in the car's colour, interior trim, mirrors, lamps on older cars, parts the manufacturer no longer supplies.

Its weakness is the unknown history. For wear parts and anything that carries safety, that weighs more than the price advantage. What to watch for when buying, and which questions to settle before ordering, is covered in a separate guide.

Which tier fits depends less on the part than on three circumstances: the age and value of the car, whether a warranty is still running, and how much work fitting it takes. A part that costs two hours of labour deserves a better tier than one swapped in five minutes — if it fails early, you pay for the labour a second time.

There is no single rule for all parts, but there is a direction that holds up in practice:

If you have a part fitted, you should know afterwards what went in. An invoice reading “front brake pads” is not enough; it becomes useful with the maker and the part number. That matters for a later complaint, for a warranty discussion and at resale, when a buyer asks about the most recent work.

And if you want to bring your own parts, ask first. Many workshops will not fit customer-supplied parts, or only without any warranty on the part, because they would be answering for goods they did not choose. That is not obstruction but a question of liability — and it is cheaper to settle before you buy than after.