Seen at a truck stop today. The LPG tanker truck driver says they have made 3 of these rigs so far, and the rear wing is "for real", not a gag. Also note the side vanes, or wings, (half way forward, on the sides, hard to see) I just don't get it aerodynamically, on a 75 K rig! When I first came upon it, I thought it was some kind of super trick sail plane trailer (viewed from the rear). Improved efficiency/MPH was the intent, and the driver claims it works. Just googled them, interesting tech. https://exosent.com/

FWIW the tank wall thickness is 1/4", and the content's pressure is anywhere from 250 to 450 PSI
.

I would venture that it helps a bunch with spray as well....one of the biggest problems for seeing what's around you when it's wet. Tanks are awful for spray. There's some weird airflow around them for sure! Plus they're really hard pulling in the right wind!!
John

Yes I bet it is for smoothing the air out too. Kinda like on the back of the 53 foot van trailers. Thanks for posting the picture of the propane trailer.

Why does "Trailer Tail" sound more like a "social" medical condition that a form of airflow management.

When air controls under trucks first started showing up on the road I asked an engineer at ITD if they actually had any effect. The answer was IF they are installed correctly the panels under the trailer reduce fuel use by 3%, and the trailer tails reduce fuel use by 1%. Doesn't sound like much until you look at the total fuel usage by all he trucks on the road. If that wing can reduce road spray riving in the rain I'm all for it.

All I know is that if I needed to haul several thousand gallons of LPG somewhere, I'd want one these tankers! There were a lot of small details I didn't mention that made it almost like looking at a custom car or fancy kit plane. The tractor was also very well decked out, though pretty conventional. The trucker was obviously proud of the entire setup.

Some time ago, I started seeing VG's on trailer sides, near the end, not so much now. I see some (rare) motorhomes have owner installed VG's, in an effort to break the suction of the square rear ends. I know when I put some left over ones on my Toyota Yaris's roof, right where it transitioned to the hatchback, they improved the straight line stability quite noticeably.

Went to Exosent website and found a little more info.

Not only does the wing look cool, it also addresses the turbulent air flow coming off the back of the trailer. It helps keep water spray and splash down for following vehicles, improves trailer stability and increases fuel mileage.

One customer, who so far has five of the trailers with the wings, says it is getting as much as 15% better fuel mileage, according to a company official.

According to its website, Exosent is latin (Exo Sentia) for "outside thought." I take that to mean thinking outside the box, to use a cliché. Founded in 2010, Exosent uses a “skunkworks” philosophy, named after a small and agile group at Lockheed Martin that took the stealth fighter concept to flying prototype in 2.5 years.

Flying back from eyeballing an upcoming crane job today about 35 miles away (which involved first landing at a crop duster's strip, and then a 5 mile Montague e bike ride, proving once again how handy the bike/plane/crane combo is for me) I came across the very same type of tanker I pictured earlier. Try as I might, I could not get the plane'
s shadow in the pic, the highway and the sun angle would just not cooperate, but I still think it's a cool shot. I will send a copy to the tanker's manufacturers, with no explanation