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slowmover · 04-03-2017, 08:13 PM

Shape is important, and I'll leave that to others better versed. Height is the highway mpg killer, before all others. After that is the need for radiused wall joins. Rolled. Top & bottom. Enclosed undercarriage. (This done, don't worry about adding Coleman Mach 8 roof air and/or Fantastic Fans).

Go have a long look at the UHaul 12'x6'x6' trailer. Great utilitarian shape. Great towing manners with tandem axle. Wide spread axle (roll center problems minimized as leaf springs are joined to axles beneath or outboard of side walls). Low ground clearance.

I used this behind my truck on two 700-mile round trips. Four legs. Two each loaded and empty. Same load. Same road and conditions. Truck is 8k solo, and combined rig was 13k. Solo mpg was always 24 (up to 27). Trailer empty was 19-mpg. Trailer loaded was 18-mpg. Always at 58-mph and never a tailwind. Gulf Coast Texas. And always traversing Houston.

About a 25-30% penalty. Doesn't get better than that. But it might with help from this crowd. Truck has cab height topper and trailer roof was same height.

I'd pretty much copy that trailer, but give it a rounded bullet nose. And an EM approved swing away tail. I'd also change to torsion axles (wheel face is now equivalent to leaf join at axle per roll center). A Towtector to build an interface upon.

And Polymetal. Somewhere. (I ain't ragging you, Freedom-of-the-Beard)

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04-03-2017, 08:13 PM	#146 (permalink)
slowmover Banned Join Date: Oct 2009 Location: Fort Worth, Texas Posts: 2,442 2004 CTD - '04 DODGE RAM 2500 SLT Team Cummins 90 day: 19.36 mpg (US) Thanks: 1,422 Thanked 737 Times in 557 Posts	Shape is important, and I'll leave that to others better versed. Height is the highway mpg killer, before all others. After that is the need for radiused wall joins. Rolled. Top & bottom. Enclosed undercarriage. (This done, don't worry about adding Coleman Mach 8 roof air and/or Fantastic Fans). Go have a long look at the UHaul 12'x6'x6' trailer. Great utilitarian shape. Great towing manners with tandem axle. Wide spread axle (roll center problems minimized as leaf springs are joined to axles beneath or outboard of side walls). Low ground clearance. I used this behind my truck on two 700-mile round trips. Four legs. Two each loaded and empty. Same load. Same road and conditions. Truck is 8k solo, and combined rig was 13k. Solo mpg was always 24 (up to 27). Trailer empty was 19-mpg. Trailer loaded was 18-mpg. Always at 58-mph and never a tailwind. Gulf Coast Texas. And always traversing Houston. About a 25-30% penalty. Doesn't get better than that. But it might with help from this crowd. Truck has cab height topper and trailer roof was same height. I'd pretty much copy that trailer, but give it a rounded bullet nose. And an EM approved swing away tail. I'd also change to torsion axles (wheel face is now equivalent to leaf join at axle per roll center). A Towtector to build an interface upon. And Polymetal. Somewhere. (I ain't ragging you, Freedom-of-the-Beard) . Last edited by slowmover; 04-03-2017 at 08:23 PM..