i have been using 100% biodiesel/wvo for my cars for 10+ years, but that was/is for cars. when i looked for a class a couple months ago i was particular looking for older cummins equipped with mechanical injections for later burning biodiesel/wvo in mind. after talking to cummins advisers and judging pros and cons, i moved to isc engine so giving up the intention. from my car bio experience, 5% bio is nothing to worry about. gunk will come out if any but it'll not happen overnight. if it does block the passage, you can tell from engine performance, then you go change the filter. for most people you only drive couple thousand miles, the gunk will not block up the filter before you change the filter on annual intervals. for those very old coaches, say 20 years old, the rubber hoses or seals are not designed for biodiesel, which may somewhat become softened. overall, i don't think 5% or 10% will damage anything.
2000 Country Coach Intrigue 40'