Frontal Area

[Padgett]

Something you rarely see mentioned with relation to trailers is the frontal area. At low speeds it really does not matter but drag becomes important over 45-50 mph.

Recently I noticed that my Jeep's owner's manual mentions that my combination is rated for 500 lbs tongue weight, 5,000 pounds towing, and 40 sq. ft. of frontal area. (TM is marginal but is mostly in the heep's airstream & front is rounded so not quite a barn door). Raising the coach a few inches would increase the drag proportionately.

Just another advantage to the TM but something to be considered when selecting a tow vehicle. Does look like the heep's rear flows well onto the TM front & wonder what difference adding a camper shell to a pickup would have in reducing overall drag.

Does anyone have a cdA figure for the TM ? I could not find one.

[TrailManorMan]

Originally Posted by Padgett

Something you rarely see mentioned with relation to trailers is the frontal area. At low speeds it really does not matter but drag becomes important over 45-50 mph.

Recently I noticed that my Jeep's owner's manual mentions that my combination is rated for 500 lbs tongue weight, 5,000 pounds towing, and 40 sq. ft. of frontal area. (TM is marginal but is mostly in the heep's airstream & front is rounded so not quite a barn door). Raising the coach a few inches would increase the drag proportionately.

Just another advantage to the TM but something to be considered when selecting a tow vehicle. Does look like the heep's rear flows well onto the TM front & wonder what difference adding a camper shell to a pickup would have in reducing overall drag.


Does anyone have a cdA figure for the TM ? I could not find one.

When I get a chance I'll put mine in my wind tunnel! Just kidding, I do know that my tow vehicle likes the TM better than a utility trailer I own concerning gas mileage, the utility trailer is tall and like dragging a parachute around.

[tentcamper]

My first camper back in the 80 was a very small popup. The box was less the 8 feet. The tongue weight was maybe 80 lbs.

It ducked in behind the full size van and I could not see it with the side mirrors. My mpg actually increased by 1/2 mpg when I pulled it. The only thing I figured that it filled the rear vacuum drag. So I think there something to the idea of having a shell on the back of a PU.

[Padgett]

Mine was too, we not only camped with it, was also a tire and tools carrier for my autocross car in '78. Believe it is a Bethany Travelling Teepee. Nice thing was the access door usable when folded.

[tentcamper]

With my TM it sits about level with the top of the van, but the AC unit is way up there. I bet that low profile AC unit you have Skip, gives you 0.25 a mile or better MPG then having a full size one.

[Padgett]

I make the AC as 1) low drag shape and 2) only about 5% of the surface area. Do not know how thick is the boundary layer back there.

[scrubjaysnest]

When we changed out the low profile A/C unit for a standard size I expected an increase in fuel use. If its there I can't detect it. But then we carry a canoe on the truck shell so that may mask things.