I have been looking to get my first diesel. I was looking at 99 and up Crew Cab's and a few Excursions with miles from 180K to 240K (my price range). It won't be my daily driver but it will be occassionally driven empty to work and mainly for towing duties for my boat and travel trailer which weigh 8K and 9K loaded. I am looking for a crew cab 4x4, SRW with stock tires/rims (or Excursion). I have read the 6.0 makes more power (stock) than the 7.3L, runs cleaner and can get better mileage. I am reading about the problems some have with the coolant, cast sanding, oil cooler, EGR cooler and am debating if I am ready for the increased attention this motors sometimes needs but I do like the 5 speed transmission. I was wondering what kind of mileage can I expect empty doing 65 mph on the highway (cruise control) to see if the empty mileage can justify me getting rid of my current suv which can free up more money for purchase or upgrades. Is it realistic to get 18-20 mpg? If not stock what can be done to increase the efficiency or get better economy?