This is an interesting oil filter comparison in which 5 filters are cut open to reveal their internal construction. Here is the order of preference: 1. NAPA Gold 2. Wix 3. Bosche and Purolator 4. Fram
All synthetic guys I advise use of the wix xp filter My resource on the drag side of k&n wont even recommend there oil filters after extreme testing the xp is top notch for drain back an filtration my 6.1 uses the Sent from my iPhone using Tapatalk
FRAM used to be the best in the 60's and 70's but failed to upgrade their product to modern specs and performance.