What are non-original parts in a vehicle repair often known as?

Non-original parts in vehicle repair are often referred to as aftermarket parts. Aftermarket parts are manufactured by companies other than the original equipment manufacturer (OEM) and are made to fit or function similarly to the original parts. These parts are usually sought after for their potential cost savings, enhanced performance, or greater variety compared to OEM parts.

The term "aftermarket" indicates that these parts are available for purchase after the original sale of the vehicle, and they can range from performance enhancements to standard replacements. Using aftermarket parts can be a practical choice for many vehicle owners, as they might offer more competitive pricing and varied options.

In contrast, while "counterfeit parts" suggests illegitimacy and unauthorized copies of the original parts, "alternative parts" is a broader term that could include both aftermarket and remanufactured parts without the specific connotation that comes with "aftermarket." "Non-OEM parts" could also refer to aftermarket parts, but it lacks the specificity and recognition that the term "aftermarket" has in the industry.