- Aug 30, 2014
- 15,653
- 22,167
And synthetic oil lasts much longer than traditional. If I went by time, my fresh unused oil change in the fall would need to be changed again in the spring with zero miles on it.... Not gonna happen.Time has very little to do with how oil gets dirty or accepts moisture. Running the engine through hot cold cycles is what really promotes contaminants in the oil. Yes, over time oil sitting in an open can will absorb moisture, but that takes significant more time.