There are actually supposed to be 2 pressure valves in an oil filter. An anti-drainback valve prefents oil galleries from emptying back and thus helps a motor by maintaining pressure on a startup. On many cars now, the filter is located such that it won't do this anyways. On a tractor? Generally not so lucky. There is also a pressure relief valve in the filter in case it gets plugged from sludge, water, filter deteriorization and heavy wgt oils and high rpm. You get more HP if the oil flow isn't dragging the engine down. And this is only a momentary lapse, anyways. Settings are different for low rpm diesel motors for obvious (I hope) reasons). On a cold day, oil is heavy, filter may be too fine and your motor is starved for oil. On a car (even a diesel), Federal emissions rules make it necessary to warm the engine asap by any means, so heavy oil on a cold day is a brief moment in time. Cars get more frequent oil changes and get better oils by nature. They are generally getting oil changes much too frequently. Ain't so with a tractor, which sees frequent high or max power duty cycles, dirty/dusty environment air, open breathers, and poorer tolerances than a car motor (plus a lot more hours on the clock).
Like I said, Having a manufacturer supplied set of filters on my machinery makes me sleep really good at night (among other things, of course. And I don't need a filter on that anymore.)...