WTB Roof Air deflector

T Hall · 06-18-2010, 08:23 PM

Where do I find the cheaper, smoked clear plexiglass type that I see on some duallies? I have searched the web with no luck. Thanks

rallye bob · 06-19-2010, 08:07 AM

Some info I have read on this subject................
You will never recoup your investment ... AND.....

Believe it or not, those rooftop wind deflectors on pickup trucks could actually DE-crease your gas mileage.

Yes. I said it could DE-crease your mileage.
The reason is because the top edge of the pickup truck model deflector does not extend above or even reach the top edge of the trailer's roof line and the deflector sits too far forward of the trailer's front.

Thus the wind "slips" over the top edge of the deflector, goes down behind the deflector and then pushes against the front of the trailer.

This causes increased drag, as if the trailer had suddenly gained several hundred pounds of extra weight.

For a deflector to work, two things are a must:

#1. The deflector's top edge must be at least even with the top edge of the trailer and if the deflector's top edge is a few inches above the trailer's roof... all the better..

#2. The deflector must be located within six to twelve inches of the face of the trailer...

The pickup truck models are normally mounted on the cab of the pickup truck which is several feet away from the front of the trailer....

This once again allows the "Slip-Stream" of air to fall down behind the deflector and then push against the front of the trailer.

There was an in depth write-up in one of the RV magazines a few years ago on this subject.

Take a look at a big tractor-trailer rig going down the road....

The newer style trucks have the air foil designed as part of the truck cab and is taller than the trailer roof and wider than the trailer sides and it is configured so that as the trailer rotates on its 5th wheel pin, the edges of the trailer clear the air foil without hitting it.

And the older trucks use either a "Wide" or a "High" deflector so that the slip-stream will either go around the sides or go over the top of the trailers..

Do yourself a favor and spend that money on things that will make your RV experience more enjoyable...

Several cases of cold beer come to mind ..
Some "Food for thought"....

lareagle · 06-21-2010, 08:46 AM

Hi T. Hall
I have a Air Defector(used) . Will sell for $100.
Call 740 633 1333
Thanks
Larry
II live east of cambridge,ohio

Bob Verwold · 06-21-2010, 01:08 PM

Tony, the air deflector on my truck seems to work OK . I adjusted it up until the bug line was gone and it helped some on gas usage (I think)

Also I have a new dist gear for your dad in the trailer, don't let my forget it !!

06-21-2010, 08:46 AM	#3
lareagle Member Join Date: Oct 2007 Posts: 298 Likes: 10 Liked 15 Times in 10 Posts	Re: WTB Roof Air deflector Hi T. Hall I have a Air Defector(used) . Will sell for $100. Call 740 633 1333 Thanks Larry II live east of cambridge,ohio

06-21-2010, 01:08 PM	#4
Bob Verwold Senior Member Join Date: Jul 2007 Location: Fayetteville Ohio Posts: 656 Likes: 0 Liked 0 Times in 0 Posts	Re: WTB Roof Air deflector Tony, the air deflector on my truck seems to work OK . I adjusted it up until the bug line was gone and it helped some on gas usage (I think) Also I have a new dist gear for your dad in the trailer, don't let my forget it !!

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06-18-2010, 08:23 PM	#1
T Hall Member Join Date: Nov 2004 Location: Columbus,Ohio Posts: 390 Likes: 0 Liked 0 Times in 0 Posts	WTB Roof Air deflector Where do I find the cheaper, smoked clear plexiglass type that I see on some duallies? I have searched the web with no luck. Thanks __________________ Tony Hall 3545 S/ST

06-19-2010, 08:07 AM	#2
rallye bob Member Join Date: Sep 2006 Location: Genoa, Illinois Posts: 488 Likes: 9 Liked 6 Times in 4 Posts	Re: WTB Roof Air deflector Some info I have read on this subject................ You will never recoup your investment ... AND..... Believe it or not, those rooftop wind deflectors on pickup trucks could actually DE-crease your gas mileage. Yes. I said it could DE-crease your mileage. The reason is because the top edge of the pickup truck model deflector does not extend above or even reach the top edge of the trailer's roof line and the deflector sits too far forward of the trailer's front. Thus the wind "slips" over the top edge of the deflector, goes down behind the deflector and then pushes against the front of the trailer. This causes increased drag, as if the trailer had suddenly gained several hundred pounds of extra weight. For a deflector to work, two things are a must: #1. The deflector's top edge must be at least even with the top edge of the trailer and if the deflector's top edge is a few inches above the trailer's roof... all the better.. #2. The deflector must be located within six to twelve inches of the face of the trailer... The pickup truck models are normally mounted on the cab of the pickup truck which is several feet away from the front of the trailer.... This once again allows the "Slip-Stream" of air to fall down behind the deflector and then push against the front of the trailer. There was an in depth write-up in one of the RV magazines a few years ago on this subject. Take a look at a big tractor-trailer rig going down the road.... The newer style trucks have the air foil designed as part of the truck cab and is taller than the trailer roof and wider than the trailer sides and it is configured so that as the trailer rotates on its 5th wheel pin, the edges of the trailer clear the air foil without hitting it. And the older trucks use either a "Wide" or a "High" deflector so that the slip-stream will either go around the sides or go over the top of the trailers.. Do yourself a favor and spend that money on things that will make your RV experience more enjoyable... Several cases of cold beer come to mind .. Some "Food for thought"....