Since I bought a 4 banger for my daily driver, my T100 is only used for what it does best (which is everything but commuting). During the off months, it may sit for up to a month w/o getting used. Other than a bi-weekly start and an occasional roll of the tires, what do I need to do to the fluids especially oil as far as service. I've heard that letting engine oil sit (I'm using Mobile synthetic) can build up water from condensation or something to that effect. Whatever it is, what would you do for your truck when it sits for a while?