In 1st Fram video, they say at time 1:35 that the efficiency test is per ISO 4548-12, which IS a multi-pass test. ALL of Frams efficiency claims are based on ISO 4548-12.
The statement about "filtering dirty oil on the very first pass" made earlier in the video has nothing to do with the test method. It was just a general comment about filtering oil.
The statement about "filtering dirty oil on the very first pass" made earlier in the video has nothing to do with the test method. It was just a general comment about filtering oil.