Both susceptible to what? Filters aren't going to clogged from the ferrous debris because most won't catch a lot of it. If a magnet is used, then that makes the loading on the filter even a bit less. Besides, oil filters tested per ISO 4548-12 get loaded with some pretty small particles in the ISO test dust used in the test, so that factors in to how they perform in terms of efficiency and holding capacity across a broad range of particulate sizes.Magnetism and Filters are both susceptible, but also no need to worry.