I have been carrying a container of oil in the trunk of my car for a few
years now. I don't do my own oil changes, and I have the container on hand
in the event that the oil gets a bit low in between oil changes (which has
not happened since I replaced the PCV valve 5 years ago).

Anyway, there is no expiry date on this container and I wanted to know if
the oil would still be good to use at this point. I ask because it has been
in the trunk the whole time, including during some extremely cold winters.