BMW X5 4.4 picked up in late March. Changed oil out in July at around 3200 miles on it with Redline 5W30 - mainly to get the break in contaminents out. It's currently at 6100 miles. I'm sure this oil still has plenty of miles left in it. It's soon to be winter out here in NYC however. Contemplating changing the oil for the winter or just keep the oil in till it hit's around 9K miles which should be right about when springtime starts. What do ya'll suggest.