I know a typical BITOGer probably knows this already, but ISO Codes are powers of two. Which means that being 3 ISO codes worse is EIGHT TIMES the number of particles. Each ISO codes is roughly double or half the number of particles of the code above or below it (respectively).Here are the averages for all filters that I have more than one PC for. The BOSS ranks second to last after Toyota OEM. I've only included the third ISO numbers here since Blackstone hasn't been consistent over the years with how they estimate counts for the smaller particles. The averages are based on between 4 and 14 PCs per filter, except for the BOSS which is an average of only 2 PCs.
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