For the longest time I thought this was just a gimmick to let old people know when to change their oil. It always went on at 5k miles after the last change regardless of driving. I started out using dino oil and then switched to M1 synthetic but regardless it would go off at 5k. I switched to GC for my last oil change and to my shock, it went to 6800 miles before it went off. Sure enough, I have already gone past 5k on this oil change with GC. I guess it is just burning less with the GC than it did with the other oils or something.