I have been a mechanic for many years. I used to buy Napa Auto Parts almost always. I felt the parts were good quality, although more expensive than others. It does not pay to install poor quality parts on a car, they come back, and bite you!  Unfortunately, a few years ago it seems Napa changed their policy on quality. This happened around the time they totally changed the on-line site.  Around the same time, I started looking at Rock Auto on-line. Rock Auto offers each part by a few different manufacturers, quality levels, and prices. I started noticing that despite Napa still charging higher prices, they were now supplying the cheapest, lowest quality parts instead of the better quality they were known for.  Given that, why would a person order from Napa, when Rock Auto is surprisingly lower priced, and you have a quality level choice . Napa seems to be riding on their previous well known name, while keeping the prices artificially high.   Some prime examples of this is, I purchased a starter solenoid, (eckland, Napa's electrical brand), as a preventative measure. The third start-up, after installing, the solenoid froze in the on position, with key off, and kept the starter spinning and engaged until I could unhook one battery terminal. Burned up the relay, starter, and a couple wires.  I purchased a rebuilt alternator, took it from the box, and turned it, it felt rough turning, as if there was dirt in the bearing race or defective bearing components. I purchased Napa's best fuel pump, and it was very noisy from day one. I purchased a set of Napa Branded, 2 ton each, jack stands. One of them had a defective casting that would not allow the stop to lock in place. Although it seemed it locked, when weight was applied, it fell.  I purchased rebuilt Ford Front calipers from Napa, and with in one year, the unplated soft steel bleeder screws has rusted solid to the caliper! I heard from a NAPA rep, and he said due to competition, quality had to suffer, BUT WAIT, isn't quality the whole point. Especialy when still charging the higher quality prices. read more