NAPA filters are supposedly made by WIX. I have been told they are the same filter with just a different paint job. Filters are mass produced fairly inexpensive items and I guess one can get a bad one from any manufacturer. I used to swear by Purolator but I got a couple of bad ones from them that wouldn't thread down properly and leaked around the sealng gasket. These particular ones fit my Isuzu diesel and were made in Thailand or India. I haven't had any problems with any other Purolators. WIX are supposed to be good filters. Right now I am using AC Delco on my Chevy but they don't cover all applications.