Review on Premium Cabin Air Filter Performance Replacement Parts ... Engine Cooling & Climate Control by Joe Martin

Usually after 12,000 miles my paper filter is covered in dirt, dust and leaf fragments. After 12,000 miles this filter seems to be picking up very little. It captures the obvious leaf fragments, which are quite large. Looking at a used filter in a bright backlight will show that large portions of the filter are fairly clean while smaller portions are black. I suspect the black color is dirt trapped in the oiled portion of this filter. I expected most of it to be black with dirt. I do not recommend and will return to paper filters. I recently watched a YouTube video testing this and other brands of paper filters, which confirmed my assessment. Too many fine particles pass through this filter.