Extended Warranty for tow vehicle?

Mtwoodson wrote:
Can anyone think of a rational reason to purchase an extended Ford warranty on a 2013 F350 6.7L 4X4. It has about 18K miles and not a hint of a scratch or oil leak. The dealer-provided Auto Check is clean (surprise surprise.) If it were a gasser I wouldn't give it a second thought, but because it's a diesel I'm a little uneasy, probably because I don't know much about diesels. Factory warranty is 36 months/36,000 bumper to bumper and 5 years/60,000 powertrain. $2200 in extended warranty would get those to 75 months/75,000 miles, doubling both months and miles for BTB. At first sniff, it doesn't make much sense, except for FoMoCo.