My friend is a mechanic who lets me use his 3rd bay to change my oil when it's not tied up. I did a run of PU ending today at 4,000 miles. I used the Pure One 30001 and I drained the oil out. Right then I got an important cell phone call so my mechanic jumped under the truck and took the old filter down and drained it. When I got off the phone he asked me what oil I was running and if I'd added any extra cleaners to the oil. I told him I was running PU 5w30 and no, I hadn't added anything to the oil. He told me that the old filter was drained and to come over and feel how heavy it felt. Either something weird was going on or PU cleaned a lot of gunk out of my engine considering how much heavier than normal the weight of the old filter was.