Automakers always have two maintenance schedules, the normal driving schedule and the severe condtions schedule. but everyone seems to think that they are driving in severe conditions, probably due to quicky lube advertising. some of these conditions are; stop and go driving (that's a catch all) dusty conditions cold or hot conditions etc. everyone drives in "stop and go" conditions, how much "stop and go" is enough to be "severe?" I understand dusty conditions but for an average vehicle on the road how much "dusty conditions" are "severe" "cold or hot conditions" does cold or hot weather make oil expire sooner? does a 110* summer kill oil? I do not fit into any of the severe catergories. I drive commute 15 miles with 6 stoplights each way and I live in an extremely mild climate. I am amazed at who is convinced that they fit into the "severe" catergory.