As previously mentioned, OEM will always be the right choice because this is a part that will work just like the one being replaced. You know what exactly what you are getting, and you do not have to choose from various manufacturers. Most OEM parts come with a warranty, typically for one year. You can expect good quality from OEM parts, but a few aftermarket manufacturers are known to exceed in this regard.
The assurance and peace of mind you get from OEM parts come at a price. Market studies indicate that OEM parts cost on average 60 percent more than aftermarket parts. There are not too many places where you can purchase OEM parts; dealership service departments are your best bet, followed by buying online.
Third-party aftermarket parts are generally more affordable and more numerous than OEM parts; as for their quality and reliability, it depends on various factors. A brake parts manufacturer such as Brembo, for example, can be described as being aftermarket, but this is a highly respected brand for luxury and performance racing cars, and their products are not cheap. Some aftermarket parts manufacturers are committed to providing quality while others are just looking to compete in terms of low pricing.
Unless they are made by performance manufacturers, aftermarket parts rarely offer warranty periods. Auto repair shops know which aftermarket parts vendors they can trust; to this effect, NAPA is known to be reliable. You will not necessarily be rolling the dice with aftermarket parts, but you may not get the same peace of mind. If your car is being repaired under collision, comprehensive or full coverage auto insurance, chances are that the insurer will only authorize aftermarket parts.
Used and Rebuilt Auto Parts
In North Carolina and across the U.S., junkyards take advantage of wrecked and abandoned cars to salvage whatever parts can be extracted. There are many players in this secondary market; individuals who bring their own tools and pull parts out of junked cars used parts dealers and rebuilders.
Used auto parts should not be used for mechanical repairs because you can never tell how they performed in the past; in this case, you will really be rolling the dice, and auto service technicians will be unable to provide guarantees. To a great extent, rebuilt auto parts are a better choice; they start out as salvaged parts that go through an inspection to determine their condition and potential of repairing faulty components.
Rebuilt parts can save you money, but you cannot reasonably expect them to last as long as OEM or aftermarket parts; moreover, there is a limit to the parts that can be refurbished. Alternators and engines are good candidates for rebuilding because they have secondary components that can be replaced; as long as their cores are in good shape, their useful lifespan can be extended.
In the end, choosing between OEM, aftermarket, rebuilt, and used auto parts comes down to how much you would like to spend and your risk tolerance. You can always ask your auto service technicians for their opinions on which parts should be installed in your car.