Changed the oil today in my son's 94 Acclaim. Used ST syn 10W30 from my stash. Oil is about 3 years old and is sl/cf rated. Looked in the bottom of one of the bottles and saw a brownish residue. Addative settled out? Will the poor old 2.5L 4 with ~188K be destroyed? Well, anyway I hedged it some. I used 3 Qts. ST syn 10W30, 1 Qt. Rotella T 15W40, 4oz. VSOT, 4oz LC20 and enough drain oil* to make up a qt. Plan to run this 1 year/10,000 miles. *Drain oil, M1 10-30, RTS 5-40, Tection 15-40 Shell 10-30 ST 5-30,10-30,10-40,15-40 ATF+3, ATF+4, Some aeroshell w100, Who knows what else.