We have had the hottest summer on record in a long time here in Texas. It was over 100 deg for more than 2 months straight! This summer i ran QSAD SN 5/30 in my wifes explorer with ALOT of stop and go driving. Because this summer was so harsh i decided to change the oil at 3k. Upon draining the oil i noticed that it looked almost new (slightly discolored) and didn't seem to broken down at all. I was actually kind of bummed becuase if the catch pan had been clean i would have poured the oil right back in. There are so many people that bag on QS (i used to be one of them) and they have never even put it to the test. just want to say im very happy with the oil and wish i could find another sale for 1.99 a QT!!