Learned a couple things last week. Wanted to take bicycles with kayaks camping. With a 2"X4" aluminum rear bumper on the camper, did not want to hang two bikes & rack on the camper bumper and did not want to put the bikes on top of the pickup shell increasing wind resistance. Found an extended hitch I could mount a Swagman XP bike rack on between the camper & pickup. It worked out nicely.
Before I had been hauling the camper with a 3/4" rise hitch. This bike rack set up worked with a 2" drop hitch, letting the front of the camper ride a little lower. Found I could use 5th gear on level & slight uphill grades @ 60MPH average @ 16MPG. Before when using the 3/4" lift hitch, I could not tow the camper up any grade, without going to 4th gear on interstates. All I can figure by lowering the front of the camper slightly, gives "less" wind resistance.
Will test fuel economy in this configuration at lower speeds in 4th gear on back roads in search of better MPG. Best fuel prices found in SC last week were $3.49 per gallon.