Aerolid mod for Trailer Towing

[aerostealth]

This is a scale drawing of the top of my Apex trailer to show the added mods for improved aerodynamic trailer towing. The scale is 1 ft per grid line. The trailer body increases from 19.5 ft long to nearly 26 ft including both the projected front and back modification. The side width is 90 inches or 7.5 wide. The second image at the right shows a side view of the boat tail only which is showing the top angle of 25 degrees to scale. The two side panels and the bottom panel will be at a 10 degree angle as shown.

I have seen in other threads a rationale for the trailer manufacturer to optimize interior space in trailers as a reason not to improve the aerodynamics of trailers. It is my position that this rationalization is not legitimate. As can be seen by my drawing the rear boat tail could be light in weight and made fold-able for storage when not in use. The front fascia can be light weight paneling also which would cover the propane tanks, and act as an additional storage area for light weight object like bed rolls etc.

The manufacturer really does not have a good reason not to include modifications like this into their trailer designs. With fascia surrounds for the AC unit if top mounted, and under belly enclosures to clean up the air under the trailer they would have a much better product that could cost the buy up to 30% less in fuel cost to tow. You can not tell me that this would not sell if it was understood by the buyers. The manufacturer could incorporate these features much better then the Ecomodder can after the the trailer design has been finalized. They could do it better, in a more durable fashion, and with a more pleasing aesthetics then most of us can in our garage. I think such a product enhancement could breathe some new life in this moribund industry.

The real reason it is not being done is fundamental lack of comprehension and insight into the physical laws governing low speed aerodynamics and its importance. In short they just are not all that sharp of pencil in their chosen field of trailer designing.

[renault_megane_dci]

Sometime there are laws that somehow freeze development.
I might be wrong but people owning RV's can afford the extra fuel cost and are OK to pay for that much comfort.
If not they would own a tent and a station Wagon ...

[aerostealth]

Seems like quite a few people have a rationalization for not doing an experiment that has never been tried. For that reason I will have to call the myth busted. The real answer may be government standards requiring a certain level of efficiency in trailers when they are towed. Owners of new trailers would be the benificiary wither they knew it or not. Just saying a couple hundred dollar modification to a 15,000 to 25,000 dollar trailer that pays for itself is not viable is not only ludicrous but just doesn't hold water.

[aerostealth]

Seen this truck and camper shell at the Post Office today. It is interesting to me because this camper shell does the same thing I modified my Aerolid to do for when I am towing but it is of course this way all the time. The two ladies driving the truck are from Texas so I am assuming they are towing a TT and camping near by, but I did not ask them.

I looked the company up and the name of the company is A.R.E. and this particular shell is a TW. There is actually a local dealer for me Borman Autoplex. As is usual it is next to impossible to get a price online. One of their advertising claims is that it can help push the air up for trailer towing. What a concept.

[slowmover]

Might help marginally in towing. But a significant penalty while solo. Given an average of 15,000-miles annually in this country, and 5,000 towing (call it somewhere around 18k total for this one) the solo penalty dominates. Unlike the Aerolid.

A picture of the back of the truck might have given clues as to whether or not a "real" tow vehicle.

ARE is a quality topper. That, and LEER are the two to have. This type shown seems appealing to the unwary because it's easier to load bulky items.

[aerostealth]

Slow mover you really need to stop raining on this parade. While I agree solo it is loser it is way ahead of nothing towing a box trailer. I don't think it is as high as my mods to the aerolid. I was just jazzed to see a commercial product replicating what I did to the Aerolid. This might be a nice topper to have just for towing. Anyway it shows I am not having a solo hallucination.

[slowmover]

You misread me, then.

Were the type shown worthwhile I'd have one. The reports on RV forums don't agree that toppers don't add much. They are a practical choice having to do with gear storage.

They don't help in aero much until a boat or canoe is on the roof; especially the latter. The add-on deflectors -- over the past twenty years of online reading have about one owner calling them a success.

The single report I've seen is where an owner took a rigid tonneau cover and propped it up and open while traveling. Reasonable testing.

Finally, the raised rear type has been around for decades. A good friend had one on his 1984 Chevrolet 6.2L diesel bought new. 400,000 miles later of a daily 240-mile commute one would not convince him to have another.

My cab high type exacts a penalty. Around .75-mpg on average without adverse winds. As the gap between truck and trailer is 60" I doubt it's of much benefit while towing. A deflector "might" be of aid, but until I modify the hitch receiver and part of the hitch to shorten the total distance (mainly an aid in better handling due to better distribution of tongue weight across both vehicles) to nearly finalize mechanical basics, I'll look to your testing as a guide.

Believe me that I'm pleased you've decided to give a fairly comprehensive set of tests. But do not mistake that my questions will presage those of other RVers. Weight, hitch set, axle alignment verification, etc, are all part of that.

You know as well as I that we can find what we want. But it doesn't mean the results are applicable to others. Examination of details is part of a that.

The type shown in the picture above us a dead end. Even full time RVers tend to put on more miles solo than towing. Retired, no permanent address. Limited income, in many cases.

The usual "solution" is to use a smaller, lighter trailer. Another dead end when a pickup is chosen as TV.

So your pursuit has application to many others. Default bad TT design choice and default bad choice of TV is the norm

[aerostealth]

I view these appliances as part of a total system and it does no good to discuss them in isolation. My mods to the Aerolid appear to be worth a 16% improvement over a empty bed. With gap closures, a boat tail, and a belly pan my truck/trailer combination should be an entirely different entity. I have seen bumped up camper shells in the past but none with a smooth rise from the truck cab to the end like this one. Maybe I am just not very observant

[slowmover]

The Aerolid has all the advantages with no drawbacks except cutting storage capacity. But few there are who fill a pickup bed and topper. A custom bed in aluminum with drawers and cabinets plus a good shape would take care of space utilization better, and provide the base for an Aerolid

Will let everyone have a look at mine after that winning lottery ticket

[skyking]

Originally Posted by aerostealth

This is a scale drawing of the top of my Apex trailer to show the added mods for improved aerodynamic trailer towing. The scale is 1 ft per grid line. The trailer body increases from 19.5 ft long to nearly 26 ft including both the projected front and back modification. The side width is 90 inches or 7.5 wide. The second image at the right shows a side view of the boat tail only which is showing the top angle of 25 degrees to scale. The two side panels and the bottom panel will be at a 10 degree angle as shown.

I have seen in other threads a rationale for the trailer manufacturer to optimize interior space in trailers as a reason not to improve the aerodynamics of trailers. It is my position that this rationalization is not legitimate. As can be seen by my drawing the rear boat tail could be light in weight and made fold-able for storage when not in use. The front fascia can be light weight paneling also which would cover the propane tanks, and act as an additional storage area for light weight object like bed rolls etc.

The manufacturer really does not have a good reason not to include modifications like this into their trailer designs. With fascia surrounds for the AC unit if top mounted, and under belly enclosures to clean up the air under the trailer they would have a much better product that could cost the buy up to 30% less in fuel cost to tow. You can not tell me that this would not sell if it was understood by the buyers. The manufacturer could incorporate these features much better then the Ecomodder can after the the trailer design has been finalized. They could do it better, in a more durable fashion, and with a more pleasing aesthetics then most of us can in our garage. I think such a product enhancement could breathe some new life in this moribund industry.

The real reason it is not being done is fundamental lack of comprehension and insight into the physical laws governing low speed aerodynamics and its importance. In short they just are not all that sharp of pencil in their chosen field of trailer designing.

There are DOT lighting requirements for vehicles over 80" wide.
My solution is to make a folding boat tail, or one you put together, that attaches to pull-out clearance light bar above and bumper/taillight assemblies below. Then you meet the lighting requirements, and provide a stiffening structure. Put an x-brace like yours in the back when done and it would be strong.
Now you have a 5 or more foot extension with plan taper, and a rear diffuser makes it a nice 4 sided cavity that should "let go" of the wake as good as it can be done.
Fold it up and stow it and you can still get into your tight spaces.