The US Army doesn't change the
oil unless
Oil Analysis says "Do It," and there's not much industry worry about etched bearings from motors sitting around. Most of what is in
oil is - drum roll - oil. The additive package is what wears out, there are sacrificial chemicals and detergents that are consumed.
If the filters were actually good enough, about all you would really need to do is refresh the additive package at the appropriate time, top off what went missing in action, and drive on, leaving the oil in the motor for hundreds of thousands of miles. It is largely what happens to transmissions - 50K changes.
As for reading oil temps from a gauge, it doesn't read the hottest points oil is exposed to, just the overall result of mixing it up and being cooled. Since most cranks and rods have oil ports directed at the piston to cool it, the oil is being exposed to some fairly warm temps to carry off heat and preserve the aluminum from overheating. Therefore, the oil will see more than 212 F if it's operated for longer than 1/2 hour at moderate speeds.
However - the topic of fuel spoiling in the tank after sitting a few weeks is becoming much more notorious. Cars that sit longer than three months get to the point of simply not being able to start at all. The fuel undergoes severe degradation and there are no long term preservatives on the market that can keep it fresh over months at a time. The small engine industry is under stress from the large number of complaints over it, and the cause of it all is alcohol in gas.
It's going to get worse, E15 was approved, and that means paying the same and getting even less BTU's of power for a gallon. Alcohol is pound for pound less powerful, but much more aggressive in deteriorating fuel lines. If there is any pre - alcohol based fuel hose in a build car, it will deteriorate, shed rubber particles, and eventually leak much faster today than on the gas we grew up with.
Oils have improved to the point that BMW has 15,000 mile changes, most cars used today are factory recommended to change at a 7,500 or more, since 1990. The upshot is changing oil sooner than necessary is a waste of money, but ignoring the current issues with gasoline as it continues to deteriorate in power and longevity is denial in the extreme. It won't be very important if someone changed the oil in 300 or 3,000 or every three years if it catches fire and burns to the ground. Fuel containment is far more important than wringing one's hands over condensation in a garage queen while the family car endures worse treatment but motors on regardless. The fact they can is entirely based on they're ability to withstand alcohol contaminated fuels better, not what oil is in the motor from the last $45 quicky changer someone visited at lunch.
It's beginning to sound like middle aged women in the lunch room clucking over bone density loss while gulping down Big Macs and slurping apartame laced diet soda. Really? You must be kidding.
As a former Army Reservist with a degree in Auto Tech, I know very well exactly what causes most of the problems with vehicles in storage - they don't get driven enough. It's not the oil that's a problem, it's batteries not getting charged, belts oxidizing from sitting in place, tires getting weather checked from lack of exercise, bulbs suddenly shocked out of disuse. Those are exactly what top the list every summer when we gathered for training, and seeing it happen to hundreds of vehicles at a time in just the first few days drives the point home. If you want to see things fall apart - leave them parked. They will, much faster than driving them.
In America, how often you change your oil is your business. Please don't try to justify it with excuses about acid, condensation, or engine damage when there is another petroleum distillate of far more importance getting worse yearly, rather than better like oil.