I own a 2021 Subaru Forester Limited that I do my own oil changes on. I learned on BITOG that the by pass setting is 27 psi on Subaru branded filters. I use Wix, Fram and Purolator oil filters and found only the Wix has a 27 psi setting. Fram and Purolator spec a lower range as shown in the comparison table below. All of these filters are of good quality and value and because I follow the owners manual to change the oil at 6,000 miles I could use them all. I'm currently using the Purolator One on my Forester.
Questions:
1. Are the Fram and Purolator filters engineered to bypass the filter at the same frequency as the Wix at 27psi? I don't want to be dumping more unfiltered oil into the engine with a lower PSI filter.
2. If the answer is yes, how is it done? Does the bypass PSI get engineered together with the filter media?
3. Why do Purolator and Fram specify a psi range and Wix only specifies one psi number?
Thank you!
Questions:
1. Are the Fram and Purolator filters engineered to bypass the filter at the same frequency as the Wix at 27psi? I don't want to be dumping more unfiltered oil into the engine with a lower PSI filter.
2. If the answer is yes, how is it done? Does the bypass PSI get engineered together with the filter media?
3. Why do Purolator and Fram specify a psi range and Wix only specifies one psi number?
Thank you!