OES VS OEM VS Aftermarket - Difference Between Car Parts

This battle has been going on for as long as I can remember since I started my carrier in the auto repair industry over 10 years ago, but I’m sure, it started long before that. Although the three have their pros and cons, one should pay close attention to what they are getting into. Let’s see what they stand for:

OES, or original equipment supplier, car parts are usually more expensive than their aftermarket counterparts, and for a good reason. They have been tested by the manufacturer, provide good warranty coverage in case the part fails and performance is usually optimized for the vehicles. These parts are only available from the dealership of a specific automobile manufacturer.

Aftermarket parts are cheaper than the OES versions and are designed by companies that may or may not be directly related to the OES manufacturer. Although aftermarket parts are widely available through many part stores including big ones such as PartSource, NAPA, etc and small local independent part stores, the quality and warranty coverage of these parts varies widely depending upon the manufacturer. Not all aftermarket parts are of bad quality and not all aftermarket parts are made with quality in mind, so buyer must be beware of the parts they are installing in their vehicles.

OEM parts, now that’s something of interest. These are the companies that make OES parts for some brands but could not for other manufacturer. So, they end up manufacturing very good quality products for auto manufacturers that they are not the OES suppliers for. The cost of these products is usually less than OES products, but offer very good warranty as they have a reputation to protect. They are also extensively tested for proper fitting and performance on different vehicles to ensure a worry free installation.

Difference between an OES and aftermarket part

A good mechanic should be able to tell you what parts came installed from factory and what replacement part would be a good choice for your vehicle. Installing a part of less than optimal quality could cause major headaches down the road, especially for parts that are essential for proper operation of a vehicle. A poorly manufactured alternator could leave you stranded in the middle of nowhere on a cold winter night, or $20 brake rotors and pads could drastically reduce the braking performance of your vehicle while causing embarrassment as you squeal to a stop at the lights.

Installing the right parts built by reputable manufacturer might cost slightly more than the cheaper aftermarket variant but could save you an expensive tow bill or save a crash when someone jumps a light but you could stop quick enough to prevent it.