My stepsister moved into her new house and found about 5 sealed bottles of mobil1 5w30 SJ "trisynthetic" forumula in the basement. Also there are another two or three that were opened and half quarts of oil are left in them. She gave the whole deal to me, I discarded the ones that had been opened. I've had this old mobil1 on my oil shelf for the past few months and i've been eyeballing it, wondering if I should use it. I store my oil in a climate controlled area, her basement is not finished, and it goes down to like the 40's down there. Very cold, but never freezing. So I just changed the oil in my truck with some mobil5000, and I used about a 1/2 a quart of the old mobil1 to top off. Should I keep this stuff and use it up, or just pitch it?