I put ~50K on a '06 6.0L (35,000-85,000) and in that time I replaced the batteries, replaced 1 exhaust back-pressure sensor, and replaced the FICM, thought I'm told that the FICM failed because I let the batteries get too bad before I replaced them. I didn't tow heavy with mine but I didn't run it in town much either.

Last edited by horse1; 04/01/15.
I can walk on water.......................but I do stagger a bit on alcohol.