positive Semi sighting!
 

While enjoying a recent roadtrip, I spotted a semi-trailer outfitted w rear aero aids!

I was cruising west on I-90 in Montana at my usual 50mph., when this one special nationally known company rig (Swift) blew by me.

I couldn't get to my camera fast enough, nor was willing to crank it up to 60-65 to catch up w him/her?; but will try to describe.


Simply put, what I saw was like a cardboard box sans its floor mounted horizonally on the back of the '53 trailer. There wasn't much taper on the sides to mimic any funnel look. At the most, I would estimate only 2-3 degrees inward.

The top, and bottom "flaps" were made different. The top, and the bottom flaps were both 2 piece affairs, with a slight gap directly in the middle.


I was so shocked to see this out of the blue, that I don't remember what type of rear door/doors that this trailer has.

I can only surmise that if it had a rollup type door, and if loads were on conventional pallets, ( which would be 2 side by side covering the entire interior trailer width) the aero aid could stay permanent as long as the rig stayed in the western states. ( trailer length laws)


I estimate that the extension length to be somewhere around 3-4 feet long!


I could be wrong, please correct me if I am; but I sort of associated the Swift company name to be part of the group of companies that generally hire "newbie" drivers such as JB Hunt.

That's why I was surprised to see this effort under that company banner, but non the less; applaud the effort!


It's certainly no where near a boattail, so I wonder what the mpg. change is worth.

Though far more common, it's also interesting to me to see the moving companies like Atlas in particilar that have the rounded fiberglass extensions with custom taillights. I'm sure it's mainly meant just to stuff just a little more load on, but it appears that mpg. wise, it might help a little bit!
It would be interesting to hear from someone in that industry that would know the facts!

Aloha!

I've seen these around.

Swift wouldn't be doing it without tangible MPG benefits.

Did'ya see this??

http://i56.tinypic.com/vi0bcz.jpg

Or like this?
http://i677.photobucket.com/albums/v...s/IMG_8443.jpg

Yup. Could also be that these are test trailers... trying to prove the benefit in their own fleet with their own drivers on a small scale first. ??

They're proven aerodynamics. Link 1. Link 2. Google semi aerodynamics.

Orbywan, this would be perfect for your RV !

Has anyone seen one of these in real life ?
https://lh3.googleusercontent.com/-h.../s144/am1a.jpg
https://lh4.googleusercontent.com/-4...800/under2.jpg https://lh5.googleusercontent.com/-y...20airwedge.gif

Thanks for sharing the pics. What Chaz posted is the closest to what I saw.

I'm happy to report I saw tons of rigs with some kind of trailer side skirts!

my 1st sighting
 

I saw my 1st Trailer Tail heading south towards Dallas on I-35 day before yesterday.
I almost 'missed' it as it was not deployed,but rather stowed on the back of a semi,doing 63 mph into a 20 mph headwind.
I kept watching to see if the driver was going to deploy a parachute in an economic wrist-slitting move,but couldn't hang around long enough to watch.
Strange.Very strange!
Autospontaneoustesticularatrophobia I think.:confused:

Probably broke it backing up to a warehouse door.

Looking at the photos I notice they have aero wheel covers but no skirts on the one trailer. It would seem to be easier to the skirts and have more advantage. Or even better, both!

I see lots of MVT trucks with the tail, deployed. They seem to be hitting the aero mods hard. More of their trucks have wheel covers and tails than any other I see on the road. Now if they would slow down they might get even better. I go 61-62 and they blow by me.

I got 7.14 mpg Friday because of a tail wind all day. Usually I get low 6's. My truck has no aero mods except that I slid the trailer as far forward as weight will allow to reduce the gap between the two. Its a 2010 Cascadia pulling an intermodal containter.

A recent thread from T-R where an O/O couple is installing some aero on a trailer:

UT-6 Undertray Diffuser

I got stuck behind a Mesilla Valley driver the other day as we made our way across the desolate terrain between Encinal and Freer, Texas on Texas 44. Had time to study his aero rear door and all the framework. Impressive. Too bad he couldn't keep to the ruts at his governed 62-mph. His steering corrections were killing his mpg. I couldn't move out to the opposite lane without getting too far out. We both had to get around a set of Baker-Hughes oilfield specialty tractor-trailer rigs and I finally got around him a few miles later.

Their company is reputedly giving away Harleys for best mpg . . more than one way to game that, ha!!

.

I saw one of those M&T trucks like the picture on page one just west of desmoines this weekend. My girlfriend noticed it at the same time I did and we both were pretty impressed.