I keep checking prices on oils like I want to build up another stash but it seems a little OCD. I have fresh Castrol Edge 0w20 in my car and I only drive it up to 5k miles a year in East TN, USA. I'm thinking I'll just run the oil for the whole year until April 2021 instead of draining it this fall and throwing away oil that still has time and miles left on it. I tried to search this subject but so far was unable to get results. It seems as though I've asked about this here before.