So I decided to spend the last 50 hours looking into oil filters. I am a research nut especially since I had a knee replacement that went bad and I'm laid up for at least 3 to 4 more months (in addition to the 6 1/2 I've already put in). In any event it appears that WIX WL 10060 has a micron raton rating of 19. I purchased one at O'Reilly's for (I'm choking right about now) $29.95. Even the counter help was surprised at the cost. Anyway it was the highest micron rating I could find although there are other micron variables to consider (it's a total education on its own). then I took a look at NAPA and found the same Wix WL10060 and same price $29.95. HOWEVER a little additional research at NAPA and I found a SPI 2100060 oil filter that's made by, yup WIX with the same micron rating. $4.99!!!. I now have both and are comparing them. The $30 filter looks exactly like the $5 filter with 1 exception - for $25.00 you get 1 additional fold (40 vs 39). Does anyone have a good reason why the $5.00 filter would be different than the $30 filter? I couldn't find any on line. If they're the same I'm just going to change the $5 filter every 1500 miles. Am I nuts or am I onto something?