Your car is a bundle of parts, and there are lots of different ways those parts can be supplied, and who can make them… so, are genuine car parts best?

ACCORDING TO MOST dictionaries, “genuine” means true and authentic, or in other words, not a fake or counterfeit. Notice there’s nothing in that definition about who makes the part.
However, the FCAI (Federal Chamber of Automotive Industries), says “genuine parts are made or selected by the vehicle’s maker and rigorously tested by that maker as an integral component of the vehicle to meet high quality, safety and performance standards.” That is true, but another, more widely used and more accurate term for such parts is OEM (Original Equipment Manufacturer) parts, or sometimes just OE parts.  
Then there are a range of companies who produce parts that are not manufacturer approved or supplied, and the usual term for these parts is “aftermarket”. Reputable aftermarket companies absolutely do not want their goods passed off as OEM, and in fact go to great lengths to market their name and products as different to, or better than the OEM equivalent.
There are fake versions of some well-known aftermarket parts too, so you can have genuine aftermarket parts as well as genuine OEM parts. What you definitely want to avoid is counterfeits of any part.
How many aftermarket parts can you see here?

What sort of car parts can you, and should you buy?

If you buy OEM there’s typically just the one part for any given need. However, aftermarket parts can be made by a variety of different manufacturers, and can be split into two types:
  • copy parts look identical or similar to the OEM part, but importantly, are branded differently so they’re not counterfeit or “non-genuine”. Often these are non-visible parts, for example CV joints.
  • different parts are, well, different – they may be styled differently, stronger, different dimensions or some other design change. Examples of different parts would be stiffer suspension springs, a revised radiator design, restyled tail lights, or different specification of oil.
So, OEM or aftermarket parts – which to choose? Here’s some pros and cons:
  • New-car warranty – OEM parts won’t affect new-car warranty. Quality aftermarket parts will be warranted for the part only, but if that part fails and causes problems elsewhere in the car then good luck getting either the car maker or aftermarket company to take responsibility. Note that you don’t need to use a dealer to supply or fit OEM parts to maintain your new car’s warranty.
  • Cost – almost without exception, OEM parts are more expensive for the same function than copy parts.  That’s because the aftermarket needs to offer something different to the OEM and if the part is the same, price is the differentiator. However, aftermarket parts are often different designs, or higher quality. In this case they may well be more expensive than the OEM parts.
  • Quality – OEM parts tend to be a consistent quality, which typically means acceptable to very good. There are however some poor quality OEM parts, and in many cases aftermarket parts are higher quality than OEM. Some OEM parts are built to a tight budget. For example, the tie rod on my Defender was quite weak, and LC100 front differentials are not known for their strength. There are some very poor quality aftermarket parts which are not counterfeit, but in general any counterfeit parts tend to be extremely poor quality as by definition they are fraudulent, and you don’t even know who made the part in the first place so there can’t be any comeback.
  • Fit for purpose – the OEM parts tend to be rather general purpose. Aftermarket parts can be more focused, and that’s what is meant by ‘different’ parts in the definition above. For example, with 4WDs it is very common to throw brand new suspension away as the OEM parts aren’t designed to handle a heavy vehicle over rough terrain for extended periods. Sportscar drivers who drive on racetracks usually replace brake pads, brake lines and brake fluid, if not the calipers and rotors themselves. Or maybe owners are after personalised cosmetic touches such as different wheels, grills, bonnets or tail lights. People that tow heavy trailers may fit an upgraded cooling system.
  • Availability – this varies, but often OEM parts aren’t as readily available as aftermarket as they are single-sourced, but sometimes it’s vice-versa. It’s not unusual to wait weeks for certain parts, so you’d often want to take what you can get. Not all OEM parts will have an aftermarket equivalent either, but in some cases there will be multiple aftermarket options. Wheels are a good example of where you’re almost certain to find plenty of choice.
Quite a few factors to consider, but that’s not all. Your choice gets more complicated again. Both OEM and aftermarket parts are available in different degrees of ‘newness’:
  • New – brand new, never been used. These will be the most expensive, but the highest quality.
  • Used – already used on another car, just a drop-in replacement. This is the cheapest option, but can be hard to find. Wreckers are a good source of these parts. These parts are also known sometimes as ‘salvaged’ parts. Used parts can be a real bargain, but must be carefully inspected to ensure they are still fit for purpose and have not been damaged either during the previous car’s life, or in storage since. There is a thriving trade in secondhand parts, usually when a modified vehicle is returned to stock form or owners decide to change parts.
  • Re-manufactured / reconditioned / refurbished – a used part that has been overhauled, perhaps with new consumable sub-components like bearings, gears, new grease, been retuned and generally made as close to new as possible. Common examples are complex items such as starter motors, gearboxes and alternators. These parts are priced somewhere between new and used.

Just because a part is made by the OEM and fits your car doesn’t mean to say it’s appropriate or legal in Australia. Some parts fit our vehicles but haven’t been approved for use in Australia, for example Toyota Racing Developments make a nice set of braided brake lines for the 86, but they aren’t ADR-approved so can’t be used here. Happily, there are aftermarket alternatives.

OK, so how do I choose which part to use when?

All that choice makes it hard to figure out which type of part to use when, at least for the layperson who isn’t living and breathing cars. That’s because part choice very much depends on the part required and the situation.

The safest way for the average consumer to figure out what to do is to find a reputable, trusted mechanic who specialises in your type of vehicle and follow their advice. Generally, such mechanics pick and choose between the OEM, aftermarket and the level of ‘newness’ depending on what’s best at any given time, although dealers will almost always opt for the OEM part. A good mechanic will ask a series of questions about what you want to do with the car, and then present some options, allowing you to make a decision based on cost, function and speed of repair.
Factors affecting part choice include cost, fitness for the intended use, age of the car, how long you want the car to last for, availability, and owner preference. For example, I recently bought a CV joint for my Ranger. The OEM part cost $600, the aftermarket $200. This was in part because of the CV joint had to come with other components I didn’t need…kind of sneaky on Ford’s part given than CVs are often snapped on 4WDs but it backfired for them when I just bought only the part I needed from the aftermarket.
I also used to destroy alternators in mud before I grew out of it, so I had two alternators and a standing deal with a reconditioning shop who would rebuild one while the other was busted yet again by Toolangi’s finest brown stuff. Today, I have friends with high-value classics who are very careful to preserve their car’s value, so they use only OEM parts because future owners will want that purity. And I have friends with runabout cars long past warranty who drop in the nearest used part to keep their cars on the road, and enjoy very cost-effective motoring as a result.
So by now it should be obvious that it’s simplistic and wrong to say that either OEM or aftermarket parts are always better than the other. However, it is true to say that you very much get what you pay for, and that company off eBay who doesn’t seem to have a proper website and has forgotten to list their phone number…that would be what is known as a false economy. Don’t take risks with car parts, it can be deadly.
Ford Ranger with aftermarket replacements for wheels, tyres, suspension and exhaust. Accessories include bulbar, winch, driving lamps and roofrack.

How can an aftermarket part possibly be as good as the OEM part?

As the lead engineer on a major car launch earlier this year told me, “the aftermarket guys can do this sort of stuff [parts] so much quicker than we can, they’re far more nimble.” And here’s a secret – car manufacturers don’t manufacture anywhere near all of the car components themselves. They outsource design and manufacture to a vast array of companies who send them components to be assembled into a complete car, and a lot of those companies also design and sell aftermarket equivalents of the same parts they send to the OEMs.
In some cases, the aftermarket company has a better name for quality than the OEM, so manufacturers actually fit those parts and boast about it in their advertising. Examples are Bilstein suspension, Dana axles and Brembo brakes. And another example – when Toyota created the 86 Race Series they didn’t fit Toyota gear to their racecars, they fitted aftermarket suspension, wheels and brakes. 
OEM parts are often built to a cost. If a car will sell say 500,000 across the globe then saving $2 on a part is a $1 million saving, which is why tiny costs are cut. But not many cars sell half a million? Quite a few do, and given the amount of part sharing between models it’s more than you’d think. Aftermarket parts on the other hand, don’t sell in anywhere near the same volume and have to be better than the OEM, the default choice, for anyone to buy them.
Another interesting point to make is that sometimes car manufacturers offer different parts for the same vehicle, for example, heavy-duty suspension for towing. This is an implicit acknowledgment that the standard part cannot fit everybody’s needs.
Simply, the good aftermarket companies wouldn’t exist if they didn’t supply quality gear, and in many cases they work closely with the car manufacturer to produce their products.
However, the key point is “good aftermarket company”. There are plenty of cheap knockoffs, and these parts can be outright dangerous to fit to your car. Also, in general the car companies have the resources to do more integrated testing of parts than the aftermarket.
Aftermarket suspension on 4WDs is almost always heavier duty, and coloured differently to make it stand out from the OEM parts.

What’s the real risk with buying car parts?

Let’s now look at what the FCAI is warning us against, which is not “non-genuine” as they call it, but in reality counterfeit parts. These are car parts not made or approved by the OEM which are nevertheless branded as OEM parts by copying part numbers, logos and the like. They’re the car equivalent of a $30 Rolex watch, but far more deadly because if a car part fails, that could lead to a crash or an expensive fix.
How to avoid? It’s pretty simple, just use your brain, just like you’d avoid a $25 set of “Ray Ban” sunglasses. If for example the OEM wheels are $400 each from a dealer, then the OEM wheels are not going to be $100 each brand new from Joe’s Car Parts. Logic says those wheels are either stolen or counterfeit. However, aftermarket wheels – not branded, or even resembling the OEM wheels – may well be cheaper than OEM. Simply, if it looks too good to be true then it is. Again, work with a trusted mechanic who will know what’s what.
There are counterfeit versions of both OEM and better-known aftermarket parts, although the former are far more common. Just recently Toyota Australia worked with Chinese people to discover a big stash of fake parts.
Just because a part is branded OEM or from a quality aftermarket manufacturer doesn’t mean to say it is safe. Any part could be worn beyond safe limits, or the wrong part could be fitted, or it could be incorrectly fitted.

Is the counterfeit risk real?

The FCAI says that “imports of counterfeit and pirated goods make up around 2.5 per cent of global imports”, which is a quote from a European trade report that we’ve linked to at the end of the article. They then go on to say that “fake car parts from Asia are a growing part of that trade”, but there is no source for this statement. This report’s 2.5% includes pirated goods which include reproducing intangibles such as software, songs and films, as well as counterfeits which are created fake versions of products.
The FCAI’s position is that counterfeit car parts are poor quality and pose a risk to the Australian consumer. There is no denying this statement and it is an important public safety issue, but the magnitude of the risk needs to be put into proportion. So we had a look in their source report and found this graph which shows what’s actually being faked:
Car parts don’t appear to be anywhere near the top of the list, and the report is very light on for mention of cars.
This graph, also from the same report, shows the top countries whose IP has been infringed:
The USA, Japan and German have sizeable car production economies… Switzerland, and others not so much. The report also goes on to talk about brands such as Rolex, Nike, Louis Vuitton and Ray Ban, none of whom are noted producers of vehicle components. 
So if we take those two graphs together, and indeed the rest of the report, then what FCAI cited as evidence does not support their argument by implication that there is an increasing number of counterfeit parts coming into Australia or that we need to start getting worried. That’s not to say that counterfeit parts don’t exist, because they certainly do, and using them is a definite risk. The FCAI says that “more than 6000 items” with an estimated value “in excess of $550,000” have been seized over two years. So that’s probably 3000 a year, not exactly a huge flood into the local marketplace, and the FCAI did not state that it was 2000, then 4000 which would lend credence to the “increasing” part of their argument.
It is hard to escape the conclusion that the FCAI’s objective is more about trying to scare car owners into using only OEM parts which are highly profitable for its members, rather than truly trying to educate the Australian public about the real pros and cons of different car parts.
Subaru BRZ with aftermarket wheels, tyres, brakes, spoilers, wing and who knows what else.


  • OEM parts are made or approved by the manufacturer.
  • Aftermarket parts are produced by other companies.
  • Aftermarket parts may be a direct equivalent of the original part, or designed differently for different uses.
  • Any part can be supplied as new, used or reconditioned.
  • Whether to use OEM, aftermarket or how new the part should be depends on a range of factors. Seek expert advice, but don’t listen to anyone that says one is always better than the other.
  • “Non-genuine” parts could be counterfeit aftermarket or OEM parts.
  • Never use counterfeit parts, which are usually sold very cheaply pretending to be OEM parts from disreputable outlets.

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  1. This is something which has happened for ever – replace bearings, change a belt, bulb etc go to the Auto Parts store. I’ve replaced radiators and exhausts with HD versions (which were cheaper than “genuine”) which outlasted the original effort by years and years (my Renault in ’77 exhaust didn’t last the 12mths warranty, and the dealer suggested aftermarket which lasted till I sold the car). Later my ’78 VW had Toyota Landcruiser piston rings which well outlasted VW’s effort. An A/C compressor I needed, I bought from FORD to fit my VW, identical other than the badge on the box – for much less (and Jaguar used the same compressor and charged double again).

    The only “problem” is that the manufacturers and dealers want to make money on the huge mark-ups on parts which they supply.

  2. Great article thanks Robert. Do you mind if I quote a little from it and link to this page in our next issue?

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