Enclosed Trailer Fuel Economy Considerations

[Spanky100]

Looking into purchasing a two axle enclosed trailer "bumper pull". The size range will be between a 7 to 8.5 foot wide and a length between 16 to 26 foot with inside height from 6 to 6.5 foot. Will be towing 70 percent interstate highways and 30 percent county roads with speed limits 40 to 55 mph. Tow vehicles will be full size pick-up without bed topper or bed cover. Both are 3/4 ton trucks - one gas engine the other with diesel.

Questions what shape will give the best aerodynamics? I see available trailers in the following: standard boxes with flat roof, boxes with rounded roof, angle down roof in front, V noses ranging from short 2 feet V noses to 7 feet V Nose. Do the different box shapes vary fuel economy by much.

Next question: Given the same box shape and height. Will upgrading from a 7 foot to 8.5 foot wide be a significant fuel economy penality? Does adding length 16 foot to 26 foot have a large impact?

This will be my first enclosed trailer and am trying to understand the balance between storage space, trailer cost, and fuel economy pentality.

Thanks

Wayne

 

[Diamondpilot]

Looking into purchasing a two axle enclosed trailer "bumper pull". The size range will be between a 7 to 8.5 foot wide and a length between 16 to 26 foot with inside height from 6 to 6.5 foot. Will be towing 70 percent interstate highways and 30 percent county roads with speed limits 40 to 55 mph. Tow vehicles will be full size pick-up without bed topper or bed cover. Both are 3/4 ton trucks - one gas engine the other with diesel.

Questions what shape will give the best aerodynamics? I see available trailers in the following: standard boxes with flat roof, boxes with rounded roof, angle down roof in front, V noses ranging from short 2 feet V noses to 7 feet V Nose. Do the different box shapes vary fuel economy by much.

Next question: Given the same box shape and height. Will upgrading from a 7 foot to 8.5 foot wide be a significant fuel economy penality? Does adding length 16 foot to 26 foot have a large impact?

This will be my first enclosed trailer and am trying to understand the balance between storage space, trailer cost, and fuel economy pentality.

Thanks

Wayne

The height will impact slightly. The shape also but the bigger issue with pulling a box is it the back end, not the front end. If it were the front end every semi trailer would be shaped a certain way. They have to be flat in the back so they can snug up to the loading dock, its just a penalty they have to pay. Look at new campers, they are starting to round the back. The main reason guys run wings on the truck is not for gas mpg, its to keep the front clean of bugs.

I have been around trailers for 25 years as a part time job. Do not waste your money on Kentucky Go-Fasters ( no pun intended ). If you towed it every day for the next 15 years you may be able to recoup your money but most will never.

The big advantage to a V nose trailer is turning radius when backing up. You can really cut them sharp.

Set your budged then get the best built, axles, and tires you can. Look for a trailer with a well built roof, this is where most fail first. Do not get one under axled. Get a spare tire with a mount, good tied down rails inside, a well sealing door or doors, roof vents, good wiring, strong floor, ect.

Shame is I know where one a few hours from you just sold for under $4000 used. It had very few miles.

Chris

 

[Spanky100]

Chris

Thanks for the experience on enclosed Trailers. Sounds like it will be hard to make the aerodynamics increased cost pay off with around 3000 miles a year towing. Most of the time keeping sun, rain, and eyes off toys and equipment when between locations. Good points about the axles, roof, floor strength, door seals, vents and tiedowns.

Sounds like I might be able to save more fuel by slowing down 5 MPH then added expense with trailer shape. Let the budget be spent on building a better trailer.

Any thoughts on the best brands for your money or dealers to purchase from. It seems like many are built around Elkhart Indiana which is not to far out of my travel areas. Will likely do the factory pick-up to save some.

For a strong floor I have seen some do 16 inches on center crossmembers and use 2 layers of 3/4 inch PT plywood. Any other better ways.

Thanks

Wayne

 

[brain55]

My experience is that you will get what you pay for in trailers. I have gone the economical route and the high end route. There is a world of difference in quality. My first enclosed trailer was built by Trail Boss in Phoenix. The fit and finish was terrible. The welds were poor and there were gaps between supports. That trailer was used up after 2 years. I did end up with more weight in it than I expected, but that doesn't account for the walls sagging and their braces cracking.

My current trailer is a Well Cargo and the quality difference is obvious, but so was the price tag. I have had this trailer 2 years now and expect several more years of use out of it. I can't really compare apples to apples. The first trailer was a 22' x 8 1/2' box tag trailer and the current one is a 28' x 8 1/2' gooseneck with custom cabinets and lighting. Both do have A/C and vents but that is all they have in common. The Trail Boss was $10,000 vs. $32,000 with the Wells Cargo.

Spend a lot of time with the brochures picking options and upgrades. I would build it with 25% more weight capacity than you expect to need, it will hold up longer that way. I like the 16" spacing and even considered going to 12" spacing on the floor supports. Double sheeting the floor is stronger, but look at the options the different manufacturers have. Some offer tongue and groove or 1 1/8" plywood it really comes down to price constraints.

Brian