Genuine vs. OEM vs. aftermarket

Same application, very different supply routes. The real difference goes well beyond price.

Engine Partners3 min read

Spare parts for marine engines are sold as genuine, OEM or aftermarket. All three can be offered for the same application. They are not the same, and the terms are not always used the same way. This is how we use them.

Genuine: the manufacturer’s own channel

Genuine parts are supplied through the engine manufacturer’s own sales channel, normally with the manufacturer’s branding, packaging and documentation. This is a well-established route and one that many owners and technical managers are familiar with. The downside is that the manufacturer's sales channel can add a substantial premium to the price of the component.

OEM: the same source, a more direct route

OEM supply offers a different commercial route without necessarily changing the component itself. Engine Partners focuses solely on OEM spare parts sourced from licensed manufacturers that also produce, or have produced, the corresponding components for the engine builder. Particularly within the Korean supply chain for MAN engines, many of these factories have been part of the original manufacturing structure for decades.

Where a component comes from the same licensed manufacturing source, its origin and interchangeability can be verified. The difference is therefore not about finding a cheaper copy of the original part, but about sourcing the OEM component without going through the engine manufacturer's own sales organisation.

Three routes to the same engineWhere the part is made, and how it reaches your vessel

Genuine

  1. Licensed manufacturerProduces the component for the engine builder
  2. Engine builder’s sales channelBranding, packaging, and a price premium
  3. Your vessel
Origin verifiable
Yes
Price level
Highest
Risk
Low

OEM Our route

  1. Licensed manufacturerThe same source as the genuine part
  2. Engine PartnersDirect supply, no engine builder premium
  3. Your vessel
Origin verifiable
Yes
Price level
Lower
Risk
Low

Aftermarket

  1. Independent manufacturerNot licensed by the engine builder
  2. SupplierOften an attractive price
  3. Your vessel
Origin verifiable
Not always
Price level
Often lowest
Risk
Higher

Aftermarket: what can actually be verified?

This distinction becomes even more important when comparing OEM with aftermarket supply.

Aftermarket parts are generally produced by independent, non-licensed manufacturers. They can often be offered at an attractive price, and in many cases they are manufactured specifically to replace the original component. The question, however, is what can actually be verified about the part behind that price.

Material specifications, manufacturing tolerances, heat treatment, surface finishing and quality-control procedures can all influence the behaviour and lifetime of an engine component. With an aftermarket product, it is not always possible to verify whether these are identical to the specifications applied by the original licensed manufacturer. A part may look the same, fit the same and even perform correctly, but that does not automatically establish that it was produced to the same standard.

For non-critical items, some operators may decide that this uncertainty is acceptable. For components operating under high temperatures, pressures, loads or rotational speeds, the consequences of an unexpected failure can quickly outweigh the saving made on the initial purchase.

The practical middle ground

This is why we see OEM supply as the practical middle ground between the high price level of the genuine sales channel and the uncertainty that can come with aftermarket alternatives.

Our approach, cut OPEX, not corners, is therefore quite literal. The reduction in expenditure should come from using a more direct OEM supply route, not from lowering the standard of the component being installed.

For owners and managers, the question is ultimately not simply which part has the lowest purchase price. It is whether the origin, quality and interchangeability of that part can be relied upon throughout its service life.

That is where we believe verified OEM supply makes the difference.

Can we assist?

Whether you need help with spare parts identification, availability, pricing or an upcoming maintenance requirement, our team is available to review your enquiry.