I have a 2000 7.3, and really like it for work around the farm/ranch. It is an automatic,4x4, and I think on my last road trip I checked the mileage was right at 17MPG. My son is currantly looking at a 2005 6.0, automatic, 4x4. What kind of fuel mileage can he expect out of it? IF driven comparably, will it get in the area my 7.3 does? Also, with the year being a 2005, is there documented problems he should be looking at or expect to address in the future, if he buys this truck?