dshelley can you elaborate on why you said you might go with a gas powered ford for the 7-12K range?
I will be towing a pretty heavy TT and not a 5er so you have piqued my curiosity.
A couple things would influence my decision. Certainly a diesel will work harder, but the 6.2 gas powered Ford 250 is rated at 12 K or a bit more, depending on gearing. The diesel option is just too expensive and the price of diesel fuel takes away the mileage advantage. No value. The diesel engine is much heavier and removes a few hundred pounds from the payload (fifth wheel pinweight?). It's worth the price only when its assigned task exceeds that of the gas powered capibilities. My next trailer will be lighter and more aerodynamic (whatever it wil be, I don't know yet) than what I have now and will be pulled with gas power. No more hunting for a fuel station, no more waiting 20 minutes for a warm cabin in the wintertime. When I bought mine, the option price wasn't so much more and fuel was much less. There was to be an econonomic payoff. That's no longer the case, and for me and my needs, it no longer makes good sense.