I'm going to bite, simply because I have a pretty big space between the roof of my crew cab and the underside of the cabin over bunk on the TC and...Last year I had the pass through window open when I was going down the road (screened of course) and got caught in a sudden downpour. By the time I was able to find a spot to pull over safely, the water coming in the pass through had soaked the step up cushion and was running on the floor so I know the wind / rain is moving through that area pretty good.I'm also aware that on a tractor trailer, the addition of an air foil / are dam and streamlining increases fuel mileage. proven fact.I've seen on the highway, numerous tow vehicles with air foils / dams on their roofs when pulling 5'ers and TT's, I'm wondering how they work with a TC or of they work at all and...Should they affix to the truck roof or the underside of the cab over, how much clearance between the cab roof and the air dam/foil is required and what should they be made from?IMO, any 'smoothing' of the air flow across the hood of the truck, over the windshield and over the nose of the TC would yield an improvement in mpg as well as handling, especially in windy or heavy cross wind conditions.I have my own ideas but what say you?

Been discussed many times. Will never pay for itself, unless you drive hundreds of thousand miles, with fuel savings. Have been everything from personal experiences to official air flow tests. Trucks using them typically go a million miles or more in there service life to justify the potential savings. Anyway that's what I found when researching it for myself.

I haven't done any research at all. I don't think I took physics. But I think the reason it works on 18 wheelers is that you are lessening the aerodynamic forces of the heavier trailer. The frontal drag on the trailer is multiplied by the weight of the trailer. Since a TC is one unit I "think" all you would do is create some down force. Much like a race car with a wing on top. I think.

Yeah Daryl, you’ll never get that twelve bucks and about two hours of fabrication time back. :RBest to just let the rain pour in your camper window. :W:):)

I have had my "air foil" (attached to my Lance 1050s) for thousands of miles.I don't worry about MPGs. It does keep the bugs off the underneath front of the TC and flows most of the air around. I think it reduces air noise.The "air foil" is constructed of stainless steel and I had a water jet cut some slots and our names to reduce pressure build up.It works for me!

Hey Jumbo, how did you attach that to the camper? Glue?

Air dam / Air foil on cab roof or camper cab over?

Labman7
Explorer
Nov 27, 2017
Been discussed many times. Will never pay for itself, unless you drive hundreds of thousand miles, with fuel savings. Have been everything from personal experiences to official air flow tests. Trucks using them typically go a million miles or more in there service life to justify the potential savings. Anyway that's what I found when researching it for myself.
TxGearhead
Explorer II
Nov 27, 2017
I haven't done any research at all. I don't think I took physics. But I think the reason it works on 18 wheelers is that you are lessening the aerodynamic forces of the heavier trailer. The frontal drag on the trailer is multiplied by the weight of the trailer. Since a TC is one unit I "think" all you would do is create some down force. Much like a race car with a wing on top.
I think.
NRALIFR
Explorer
Nov 27, 2017
Yeah Daryl, you’ll never get that twelve bucks and about two hours of fabrication time back. :R

Best to just let the rain pour in your camper window. :W

:):)
JumboJet
Explorer
Nov 27, 2017
I have had my "air foil" (attached to my Lance 1050s) for thousands of miles.

I don't worry about MPGs. It does keep the bugs off the underneath front of the TC and flows most of the air around. I think it reduces air noise.

The "air foil" is constructed of stainless steel and I had a water jet cut some slots and our names to reduce pressure build up.

It works for me!
gitpicker2009
Explorer
Nov 27, 2017
Hey Jumbo, how did you attach that to the camper? Glue?
JumboJet
Explorer
Nov 27, 2017
gitpicker2009 wrote:
Hey Jumbo, how did you attach that to the camper? Glue?

There is a trim piece that joins the two pieces of filon (nose cap and underneath) and the edge trim. I matched the screw holes in the trim pieces.

I built it originally for the 2007 Lance 1055 I had.

When I purchased the Lance 1050s, I had to add pieces to lengthen. The 1050s is wider that the 1055.
deserteagle56
Explorer II
Nov 27, 2017
The last thing I would worry about is whether it would pay for itself. I want something that will keep the air out of that space and reduce the noise.

A year ago I was heading west on I-80 across Wyoming. There was a storm system approaching from the west - the freeway signs warned of steady winds from the west at 50 mph gusting to 70. The speed of the truck combined with the speed of the wind - well over 100 mph. The noise from the air caught between the cab roof and the camper was horrendous - the air pressure was actually making the cab roof vibrate - flex up and down. If an air dam could prevent that I'd sure give it a try.
narcodog
Explorer II
Nov 27, 2017
Do a search for Sleepy's airfoil, more info than you can absorb. It will cost less than $20.00 to build.
work2much
Explorer
Nov 27, 2017
narcodog wrote:
Do a search for Sleepy's airfoil, more info than you can absorb. It will cost less than $20.00 to build.

Since it took a while to find here is the linkhttp://www.rv.net/forum/index.cfm/fuseaction/thread/tid/17575645.cfm
SidecarFlip
Explorer III
Nov 27, 2017
Menards has 'Sleepy's mesh plastic, called 'Gutter Guard', it's $1.93 per 4 foot length.