We recently made the trip from Spokane WA to Haines Alaska towing a 18' boat on a trailer, dealer said boat/trailer/motor were not over 2,200
lbs.
The bed was also packed full, enough to squat the rear a little past level ,before the trailer was hooked up.
We averaged 17.5 MPG at 60 MPH . It's not a good highway for MPG , lots of on and off the throttle, curves, hills, frost heaves,
so I'm sure steady speed on a interstate would get better numbers.
No problems but I still think the ride is too harsh .

 

That's pretty decent, IMHO. That's inline with what I get when pulling my boat at about 200lbs less.