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Old 05-11-2017, 03:56 PM   #1 (permalink)
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10 mpg. Unacceptable

Hey there! Well I have a 14'x7' cargo trailer that I converted into a camper. It weighs around 2000#.I pull it with a chevy traverse and get around 10 mpg. I put vortex generators on to see if that would help (no improvement in gas mileage but they made it more stable) now I put a boat tail on it to see if that would help. Thankfully someone is going to put a picture up(I don't know how). So I'd appreciate any comments, concerns or criticism.

I didn't try it out yet.

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Old 05-11-2017, 06:36 PM   #2 (permalink)
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From what I can tell about vortex generators is they are used to fine tune the air flow on a good design.
Vortex generators by nature actually increase drag.
It requires perfect placement to get them to reduce overall drag.
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Old 05-11-2017, 08:24 PM   #3 (permalink)
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Quote:
Thankfully someone is going to put a picture up(I don't know how). So I'd appreciate any comments, concerns or criticism.
The comment concerning my criticism would be "Posts: 3" You're not there yet, post moar.

aero mods for traverse/acadia/outlook/enclave?

enclosed trailer aero kammback

Improving a box cargo trailer

Aerolid mod for Trailer Towing

There exists on this site a picture of a box van car hauler trailer with a split-gate clamshell rear opening boat tail, but scanning 20 pages of searching results didn't turn it up. I used [aluminum trailer boat tail -single] as a search criterion. The above is your consolation prize.
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Old 05-11-2017, 10:32 PM   #4 (permalink)
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Quote:
Thankfully someone is going to put a picture up(I don't know how).
As promised!



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Old 05-12-2017, 12:07 AM   #5 (permalink)
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That square front isn't helping at all. How about a small bubble up high on the front.
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Old 05-12-2017, 05:49 AM   #6 (permalink)
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Dear gawd. It's a brick! a 2000lb brick!

First observation: You're moving a 4700lb SUV with a 3.6l V6 (unless there's other variants), which is barely adequate for the job. Then you add another 2000lbs in the shape of a huge brick. You're lucky you're getting 10mpg. You're lucky you can pull it at all.

In this case, unlike most others, a bigger engine would probably get better fuel economy. You don't have the excessive amount of torque necessary to move such a big load, so the engine has to make up for it by revving higher than a V8 would, and throwing your engine out of the efficient operating zone. So you're pissing away extra gas to compensate.

The weight is a bit of a concern as well. An extra ton added to any vehicle is going to be hard on the fuel mileage. But you can't do much about that or about your engine, unless you want to change vehicles and or the trailer. I'm assuming not...

So. You're down to aerodynamics, basically. Do something about that "brick" shape....more than the slight boat tail you've got pictured. Fix the front. Fix the rear.

Said simply, though it isn't going to be a simple job. Might not be worth the time and effort, unless you do a lot of driving with it.
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Old 05-12-2017, 11:56 AM   #7 (permalink)
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Those square sharp corners are killing your gas mileage. Get at least a four inch radius on the side and top leading edges. This would be relatively easy to do by adding a bubble to the front. Ideally, all edges would be rounded, but the front edges are most important.
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Old 05-12-2017, 12:03 PM   #8 (permalink)
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Another thing we need to know is the speed at which you are towing, I have towed a 5x8 Uhaul across the country at speeds up to and speed controlled at 95MPH, got 10MPG doing it with a 2000 ranger super cab 4x4 4.0L V6 with a cab level camper shell, had the truck locked in drive and went on, so as I have said, what speed are you towing at?
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Old 05-12-2017, 12:27 PM   #9 (permalink)
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Apparently you have, instead of a boat tail, a stepped box cavity. The 'next' step should be finishing the fourth side.

But now I want to see a picture with the entry door open, to see how that works.

A bubble or wedge front face would work, but Great Success was had here by Hersbird:


Camper build using old Hi-Lo

Jacknife your rig and observe the clearance you have. If it's inadequate use an ogive curve.
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Old 05-12-2017, 03:30 PM   #10 (permalink)
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Thanks

First of all I'd like to thank everyone for the input, especially babydiesed for the help. Ok, now it is a v-nose trailer (just hard to tell by the pictures) and how I came up with the size, angle, and placement was by researching tractor trailer aerodynamics which I basically am. Again this is a camper used in the real world. It would not be feasible to cover my lights or to have a 10' tail sticking out the back. I'm just an old retired guy with plenty of time to mess with things. Please keep the comments coming, and like I said, I didn't try it out yet but we should be going camping by the end of the month and we will see what happens.

Thanks again

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