I'm gonna do it, but am just curious whether or not I may be wasting my money...
is it really necessary to change the oil on an infrequently used vehicle based on time between oil changes rather than mileage if the vehicle is warmed up to full operating temp. every time it is started? Specific vehicle in question is my old pickup truck; I maybe put 1-2K miles on it in a year as I probably drive it maybe only every other week or so, less in winter. Seems a shame to dump perfectly good oil... is it really necessary? I'm trying to imagine what the differences could be between sitting in a bottle on the shelf and sitting in a sump, and the only things I can think of are exposure to oxygen (does that do anything harmful to the oil?) and condensation (which should boil off every time the truck is actually driven.) anything else I'm disregarding?
nate