Auto Part Brands: OEM, Aftermarket, & What Makes Quality

Silver box Genuine VW/Audi parts, whether they're made by VW themselves or by one of VW's Original Equipment Manufacturers like Bosch or Behr or Pierburg, are all engineered to meet VW's specifications and high quality standards. OEM parts are usually only available directly through the vehicle dealership network, and are usually equal to or better than the part installed at the factory. If you were happy with the service life of the original part then this may be a good option for you.

VW makes many of these individual parts or sub-assemblies of parts themselves, but they also contract out to specialist manufacturers for many components. VW gives these Original Equipment Manufacturers design requirements, and they build parts to these specifications and ship them to VW for final assembly in the car or for dealer parts departments; any extras they make on top of what VW needs they often sell as Original Equipment Supply parts directly to customers.

As an example, many VWs use Sachs shocks and struts, with Sachs both shipping them to VW assembly lines for installation in new cars and to VW dealer distribution networks for parts counter sales and dealer repairs. They purposely make more shocks than VW needs, and the extras get sold to parts stores and websites as ZF Sachs branded shocks in blue boxes.

OEM: Original Equipment Manufacturer

OEM parts are just that: Original Equipment. These parts are as good as or better than the original part that was on your car, and are made either by Volkswagen themselves or one of VW's OEM vendors. These are the parts you'd get if you went in to a dealer and bought them at the parts counter.

Sometimes, VW can change the manufacturing source of a part for a variety of reasons such as engineering changes, quality issues, cost advantages, changes in technology, changes in currency exchange rates or even trade restrictions between countries. This ongoing supersession can sometimes cause disagreements about the correct part number.

Thus, OEM parts are not always the same as what was originally installed at the factory. Consider the difference between the “original equipment manufacturer” and “original equipment from the manufacturer”: one means that this is the same as the part installed at assembly and the other means it is what is currently supplied by the dealership as the recommended factory replacement part. For instance, if the factory OEM has broken down the tooling and jigs after the original production run of a part, VW might turn to another manufacturer to make another run of parts for their dealer parts counters.

Vehicle manufacturers will also sometimes completely redesign parts because of chronic failure. Usually this only happens while the model is still under warranty but occasionally happens later. In these cases, the replacement part may be very different than part you are replacing. A plastic thermostat housing, for example, might end up as cast aluminum in a subsequent revision.

OES: Original Equipment Supplier

VW, like most car companies, does not make every single part of their cars themselves, instead contracting out to specialty manufacturers for individual parts or sub-assemblies of parts. This is true with many complex industries and automotive is just one example: specialty manufacturers can produce parts more efficiently, faster and many times have more experience to produce a better part. Parts directly from these these OES sources are a great value proposition, giving you OE quality without OEM dealer parts counter markup.

A good example is the OES ContiTech timing belts WPD sells. ContiTech produces these belts for VW, packaging them in VW boxes and selling them to engine assembly factories, dealer parts counters and service centers. Any extras they produce get packaged in ContiTech boxes for sale as individual belts or in timing belt service kits. This is the same belt, but by skipping a step (and the markup!) of the dealer parts counter and buying from the source, you pay a lot less.

In some cases, the OES supplier may only provide an individual part, with another manufacturer supplying other parts to make a complete sub-assembly. With these ContiTech timing belts, Continental/CRP may not include bolts or tensioners or rollers, as VW only contracted to them for the belt and often sources rollers from bearing specialists like NTN or SKF; Continental/CRP may not even know which supporting parts VW uses since VW only supplied them specifications on the belt itself. At WPD, we have knowledge and experience to deal with these potential pitfalls, so we'll include the right brands of tensioners and rollers in an OES timing belt kit to go with the ContiTech belt.

OES may include supplier changes for parts supersessions. Say, VW sees enough warranty claims on axles in non-turbo cars and decides to start using stronger axles from the turbo variant of the same car. If VW originally sourced the turbo and non-turbo axles from different manufacturers, switching to the turbo axle for both means a manufacturer switch if you have a non-turbo car; it's still considered an OEM or OES part because it's an official supersession from VW and it's the same part they'd give you if you went to a dealer parts counter. After this kind of change, we've sometimes seen the original manufacturer remove the OEM label from their packaging and continue to sell the old part as an aftermarket replacement.

Being OES for one part does not make a supplier OES for the entire vehicle. Some retailers will label a parts manufacturer as OES since they are OES for some parts on the car, but they won't differentiate for each model or application. Pierburg, for example, makes many sensors and solenoids for modern VWs, but Bosch usually makes the factory-fitted mass air flow sensors. Pierburg does make an equivalent MAF which they sell as an aftermarket replacement, and it's a good part...but because they weren't the original supplier for MAFs, we won't label Pierburg MAFs as OES.

At WPD, we attempt to match OES parts to OEM parts and make sure they are equivalent. We don’t like to list something as OES when it isn’t equivalent to OEM. Many parts suppliers are blurring or eliminating the line between OEM and OES though this isn’t really full disclosure. This is why WPD is moving away from the deceptive OEM terminology and using the term Genuine.

Any part that isn't Genuine VW OEM is technically “Aftermarket.” Many people assume that aftermarket parts aren't as good as OEM, but aftermarket simply means "not original equipment", and parts under that broad Aftermarket classification can come in a wide variety of quality levels. 

Aftermarket parts manufacturers are looking to fill what they see as a gap in the OEM offerings:

• Price gap: selling parts cheaper than OEM or OES
• Demand gap: soaking up extra demand for parts beyond what OEM/OES can supply, like for brakes, belts, or other wear items that need frequent replacement
• Quality gap: selling stronger versions of parts to replace originals with a high failure rate

HQR: High Quality Replacement

HQR parts aren't performance parts designed to bring more speed or power to the table, but we consider them to have superior quality and durability to even OEM offerings.

An example: Lemförder has made suspension control arms for many different VW models over the years, both for VW's assembly line and dealer parts network as OEM parts, and some extras in their own boxes to sell on the aftermarket as OES parts. WPD offers these OEM control arms for customers who demand the peace-of-mind of OEM silver box parts that fit every time...but we also offer aftermarket control arms and tie rods from Meyle, a German company with an excellent standard replacement and HD product line.

Meyle control arms were never installed on VWs from the factory, but in our experience they've demonstrated a generally better lifespan than OEM, particularly in the area of bushings and balljoints. We'd call parts like these Meyle suspension parts High Quality Replacement parts.

AMR: Aftermarket Replacement

Aftermarket parts are good-quality and reasonably-priced alternatives to OEM or OES parts. We only sell parts we believe in at WPD, so rest assured our selection of AMR parts and suppliers has been as carefully vetted as our other parts: we research cutomer feedback and failure rates under warranty when choosing which parts to offer to customers.

An example of an aftermarket part: Behr, the OEM for radiators for many VW models, might supply radiators straight to the VW assembly lines and dealer parts network, and then sell extras they produce in Behr boxes as OES. Another radiator specialist like Nissens may see an opportunity to make their own, similar versions of the Behr OES/OEM radiator, using their own factories and supply chain to try to make a radiator that functions and fits the same way as the original but at a better price.

Here at WPD, we're using our years of expertise with which parts work on customer cars and which ones come back as warranty returns to let you in on the secret. The Nissens example above is an Aftermarket Replacement part, a drop-in replacement to get you car rolling again without breaking the bank.

AMP: Aftermarket Performance

Aftermarket Performance parts fit in place of the original parts, but with capabilities far exceeding the original parts.

An example of this is in shocks and struts. Sachs is the OES for VW for many applications, classifying brands like Bilstein as aftermarket since Bilsteins never came installed on VWs from the factory...though, with Bilstein's HD line of shocks and struts offering sporty handling with great durability, calling them simply "Aftermarket" with other manufacturers like Monroe or KYB seems innacurate.

Bilstein's HD series of B6 and B8 shocks we therefore call AMP, thanks to their sturdy construction, firm damping, and ability to tolerate hard cornering and lowered ride heights. Pair these with other performance parts like H&R Sport springs and Whiteline sway bars to give your VW serious cornering chops!