Today I stopped in at Autozone for a new headlight bulb and saw 4 cases of M-1 0W-40 sitting in front of a table just as I walked in for $2/qt! I was planning on using TSUV 5w-40, but for this price 0w-40 should be fine (2003 Discovery). The person at the register said they were being discontinued.
-John
-John