.....was just thinking, wasn't the last eruption Spurr in '92??. If that's the case I don't think Ford had any Turbo Diesels in their rigs then. Imagine what the ash would do to one of these new turbo diesels..... . Time to stock up on a few air filters I'd say. If you don't use them, so what. You just hang on to them and can change them out at regular intervals.