The aero drag on my brick-like Mombasa Expedition Tent (ARB, Camping Lab, etc.) is one of it's biggest cons in my experience. I'm wondering if a deflector like this one- www.expresstoolsandcamping.com.au/my_cube.htm would help much.
Wind Deflector for RTT
- Thread starter cnskate
- Start date
Ya, that is a cool tent. I like the honeycomb aluminum floor feature, among other things.
Any aerodynamic engineer types on here? I'm thinking of a wedge or sloped shape type deflector similar to the above, since my tent sits about five inches above the roof of my Jeep Xj because of the the high rain rails, and I want to deflect both the air coming straight at the tent and the air coming up off the windshield.
Any aerodynamic engineer types on here? I'm thinking of a wedge or sloped shape type deflector similar to the above, since my tent sits about five inches above the roof of my Jeep Xj because of the the high rain rails, and I want to deflect both the air coming straight at the tent and the air coming up off the windshield.
Martyn
Supporting Sponsor, Overland Certified OC0018
I often thought about building a spoiler for the RTT's and had sketched out some designs, but in talking to the owner of Eezi Awn his experience was this.
On a 7000 km trip through Namibia two identical vehicles with RTT's one with a spoiler and one without, the differences in fuel consumption were negligible.
So I moved on.
On a 7000 km trip through Namibia two identical vehicles with RTT's one with a spoiler and one without, the differences in fuel consumption were negligible.
So I moved on.
CYi5
Explorer
You're right, it definitely needs something. When I ran it ontop of my truck my gas mileage was horrid. Friends in my convoy tried to draft me it was so high up there 
.
I put a basket on the front of the cab after that and it did help out a bit.
I don't think i'll ever put another mombasa style tent on this 4runner, the 12" height is quite big to be practical.
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I put a basket on the front of the cab after that and it did help out a bit.
I don't think i'll ever put another mombasa style tent on this 4runner, the 12" height is quite big to be practical.
How much of that trip was on pavement at freeway speeds? I think that sort of driving is where a spoiler would help most.
roadkill
Adventurer
see my post in this thread http://www.expeditionportal.com/forum/showthread.php?t=32487&highlight=airtab
rain76king
Adventurer
on my cherokee, I put up a thule deflector, did the same trip twice and tried to drive the same way twice.....didn't see any noticible difference in mileage. I don't think it would hurt to keep one there anyways.
goodtimes
Expedition Poseur
But at what speeds?
My TJ (3.5" lift, 285/75R16 tires D rated tires, 4.10 gears, Easi-Awn 1200 on top) gets 16 - 17mpg on the freeway, at 65 - 70mph. Without the tent, it typically gets just over 17mph, at the same speed. Negligable difference, as you mention.
But, if I bump that speed up to 75 - 80mph, without the tent, I'm getting about 15 - 16, with the tent, 13 - 14. That, IMO, is enough to be significant.
Now personally, I am OK with driving in the slow lane on the freeway (in the jeep). But the darn noise created by mounting a Easi-awn over the top of a jeep soft-top . . . eesh! I wear ear plugs! (seriously). I think something to smooth out the airflow would be a good thing . . .
Mr. Leary
Glamping Excursionaire
Its not going to hurt anything being up there, and there may be benefits. Why not?
If nothing else, it will help with the issue of bug goo all over your tent cover!