I cut open 2 of these filters using the exhaust cutter from harbor freight. It worked well with these filters and didn't make the cutting wheels wander. First one came off my 2008 2.4L Accord after about 9800 miles. Apr to Aug 4 months The second came off my brothers 2003 2.4L Accord with about 10k miles. Aug to Aug 1yr They looked identical except that the filter from my brother's car caught this. Maybe loosened up some gunk from inside. I know it was run on conventional most of it's life until last summer, it now has about 160k on it currently.