Is it really a contest? 99% efficiency at 20 vs 35 microns. The rest of the filter is give or take on both. The Fram can is stronger than the wix, but already weaker vs other filters so I'm not sure there is much on the wix to recommend it. If you're concerned about slightly less filter media with the wix, you can change your oil 2 months earlier, but you can't make the can stronger or make it filter out smaller particles.