DOWNgrading truck - sanity check please

Based on mileage alone it's a poor choice. You'll save maybe $500 a year on fuel with the F150 and that's being generous. Now if you don't like the Ram because it's given you trouble or you just want something newer go for it, a new F150 should handle that trailer fine if properly outfitted. But don't kid yourself about it being the economical choice.

And to echo the above, if your goal is mileage for $10k you could get yourself into something that would save you a more meaningful amount of fuel expense.