The Truth About OEM vs. Aftermarket Parts: What New Car Stores Won't Tell You

'We only use genuine OEM parts!' is the battle cry of franchise new car dealerships trying to justify charging you double for basic service. But what does OEM really mean, and is it always the right choice?

What is an OEM Part?

OEM stands for Original Equipment Manufacturer. These parts are made by the vehicle's manufacturer (or outsourced to tier-one suppliers like Bosch, Denso, or Brembo) and sold in brand-labeled packaging. While they guarantee fitment, they carry a heavy franchise markup.

The Aftermarket Advantage

An aftermarket part is produced by an independent manufacturer. Some aftermarket brands are cheap and low-quality, but premium aftermarket manufacturers actually study why the factory OEM part failed and redesign it to be better than original.

• Fixing Factory Defects: For example, if a vehicle manufacturer used a plastic water pump housing that cracks easily, aftermarket engineers will redesign it using high-grade aluminum.
• Massive Savings: Because aftermarket companies don't pay royalty fees to vehicle brands, they can sell the exact same physical part for 30% to 50% less.

Our Parts Philosophy at Extreme Auto Pros

We do not use cheap parts, but we also refuse to blindly buy marked-up dealer OEM parts. We use our deep industry knowledge to source parts from the exact same factories that supply the auto brands, saving you money while maintaining maximum reliability.