Well both my cars only see about 2000 miles a year each. So I don't change my oil by a set amount of miles, I just change it every spring and always use synthetic (maybe I can go longer? Some say every 6 months, every year, some even say every 2 years) but anyway what about the oil filters? change them once a year too? I usually use whatever good filter like royal purple, or any other synthetic media filter that might be on sale or in the Bimmer's case w.e i can find. To throw it out after 2000 miles seems wasteful even if its only once a year. Could I just change the filter every other year? I mean the oil never comes out that dirty so it should be fine.. My only thought is maybe the filter degrades over time too? which im sure it does but it should last 2 years no? idk what are your thoughts?