Roof attachment increases MPG

[billy1]

The quote below indicates great increase in MPG. Has anyone used such with an AS? What were the results? This fella used it with a rectangular shaped trailer.

Originally Posted by TRfour

I had great increase in fuel mileage with an roof mounted air deflector when we pulled a 28 footer up to Nova Scotia and back, sometimes twice a summer for vacation. It paid for itself in fuel savings on one round trip, ball park, 1800 miles!

Side note; Here in Texas, the April bugs are out! They call them June bugs up north! ... Well, don't ya know that this deflector also keeps them critters and others from embedding themselves all over the front of your trailer! Much less elbow grease, used to clean!

Attached Images

[Airslide]

Hello Billy1,

I like that wing. What brand is it?

Thanks Vinnie

[RickDavis]

Many years ago I built one and could tell no significant difference with my 29 foot Airstream. Of course I also had a cab high cap on the truck.

Keep in mind this guy is pulling a fifth wheel, Not only big and square but A lot of resistance when the air flows around the truck cab and goes below the bedroom area that is over the truck and hits all of the lower front.

I have delivered fifth wheel in Texas in june bug season and when you go to the car wash brown water runs off the trailer as you dissolve them.

Any device like this is going to have to make a significant improvement in fuel mileage to pay back the original cost

[billy1]

I do not know anything about it including the brand. I only know what I quoted...it is not mine.

[JFScheck]

I think my cap in the back and the height of my truck would make such an attempt at aerodynamics not worth the time, in fact - such a wing if you don't know what your doing can actually mess up air flow and provide worse mileage!

Air flow dynamics is very, very complicated...

[Airslide]

It was suggested that in my situation I get a nose cone for the box but wouldn't be opposed to a wing.

[Gene]

Originally Posted by JFScheck

Air flow dynamics is very, very complicated...

I think the deflector would just complicate air flow because of the space under it and the distance to the trailer. The long distance between it and the trailer would cause all sorts of turbulence, maybe more than a pick up without it. I have seen a few of these on the road, but never had a chance to ask anyone with it what changes they saw in gas mileage.

It is said a tonneau (which we have) or a well fitted cap on the pick up should improve air flow and mileage, but the space between the back of the truck and the front of the trailer probably causes all sorts of drag that is nearly impossible to eliminate. Maybe a deflector could be mounted at the back of the pick up, but it would have to be as high as the trailer. It would be heavy, obstruct rear view and be difficult to attach. The ugliness of it would probably attract few buyers.

If the trailer were mounted on a fifth wheel like on over the road, large truck, a deflector would direct air over the top of the trailer. That makes sense, but in that case the trailer is very close to the back of the truck cab.

Gene

[noreen&sal]

OMHO, but the "nose" of an AS is its own deflector. Sal.

[Dan and Liz]

We had one. It might work with a square SOB or 5th wheel, but the only difference I saw towing about 7,000 miles with the Airstream was that it lightened my wallet by about $350. I sold it.

[JFScheck]

Sweet!

[ROBERT CROSS]

My roof deflector...yes it does help mpg and keeps the bug's off.

Bob

[Skater]

Originally Posted by Dan and Liz

We had one. It might work with a square SOB or 5th wheel, but the only difference I saw towing about 7,000 miles with the Airstream was that it lightened my wallet by about $350. I sold it.

I'm not surprised, but I'm glad to hear this. I thought that was part of the reason Airstreams were better to tow - the round shape helped wind flow more smoothly over them.

[SteveH]

It has been my expereince the worst wind is what I call a quartering head wind, coming from either 10 o'clock, or 2 o'clock off direct head wind, and I think that is because the wind can actually get between the tow vehicle and trailer and cause a good amount of drag. A direct head wind is not near as bad, in my experence.

The above deflector would do absolutely nothing to improve conditions in a quartering wind, IMHO.

[Minno]

Originally Posted by ROBERT CROSS

My roof deflector...yes it does help mpg and keeps the bug's off.

Bob

Bob, do you drive with the tailgate open too!

Chris

[rumrunner]

Bob, I have that exact same deflector-10 ft, built in 1947.
might try to polish it this year to match
tim

[ROBERT CROSS]

Originally Posted by Minno

Bob, do you drive with the tailgate open too!

Chris

Only when "Fado's" in his crate INSIDE the Burb and not on the roof.

Bob

[rumrunner]

Bob, I have the same style deflector, 10 ft made in 1945. thinking of polishing her to match
tim

[vswingfield]

Originally Posted by Minno

Bob, do you drive with the tailgate open too!

Chris

It would keep the airflow over the top intact and reduce turbulence between the TV and 'Stream.

Looks like a great deflector to me, Bob. Gonna polish it?

[ROBERT CROSS]

Originally Posted by vswingfield

It would keep the airflow over the top intact and reduce turbulence between the TV and 'Stream.

Looks like a great deflector to me, Bob. Gonna polish it?

Naw...it might outshine the Stream.

Bob

[Gene]

With the tailgate up, the vacuum behind the Suburban will increase and no hitch is necessary. That gets rid of all that extra weight. The trailer will "draft" behind the tow vehicle.

The exhaust gasses will be sucked into the Suburban and calm Fado and other occupants, ensuring a quiet and peaceful vacation.

Gene