New Bigfoots

[rabbit]

Originally Posted by Daniel A.

I really like the extra width inside and would have trouble going to a narrow unit.
I'm sure the extra width hurts my gas mileage plus the need for wider mirrors pulling the Bigfoot.

I found the first FG campng trailer I ever entered slightly less conducive to claustrophobia than a submarine but not much. My wife and I are both well under 6' but enjoy the mileage-killing width of our trailer. I'd like to hook on to a Casita some time and see if my mileage increases appreciably (20%) with the major variable being frontal area of trailer.

jack

[Francesca Knowles]

"Aerodynamic shape" at speeds under sixty is so insignificant a factor as to fall well down my list of considerations....if indeed I'd consider it at all.

Weight, however, is a different thing altogether!

Francesca

[Tom Trostel]

I neglected to mention the difference in height between the Bigfoot and the Compact Jr. Measured from the ground the Bigfoot is 8' high and the Compact Jr is 6'6" with the upper roof down for towing. That, added to the 2' extra width, and 1100 lbs. extra weight accounts for the mpg change. We haven't camped in the Compact Jr since we bought the Bigfoot. Not too hard to tell which we prefer.

http://s293.beta.photobucket.com/use...64026257680507

http://s293.beta.photobucket.com/use...09528936596045

[David Tilston]

That first picture of your Bigfoot could be on calendar.

[Donna D.]

Two things to remember about molded trailers and better fuel mileage: 1) Slow down! 2) Make memories, you can't take it with you....

[accrete]

Originally Posted by Donna D.

Two things to remember about molded trailers and better fuel mileage: 1) Slow down! 2) Make memories, you can't take it with you....

Donna, i hope this topic comes up at the NOG in April. The "Slow Down" part is something i'm trying to get into my CariBear's mind as being a Win/Win.
Win #1) Slow down and see the view.
Win #2) Slow down and see better mileage.

She has a LEAD FOOT!

On a positive note, Our rig is soooo big already it should cast a wind break for the FG that is on its way to our driveway!
The van stands at 9.5ft tall and 6.5ft wide... Fully loaded for adventure...
The van gets ~16 to18mpg on the highway at 55mph.
And ~14-15mpg at 65mph ,(

[ruscal]

Originally Posted by Francesca Knowles

"Aerodynamic shape" at speeds under sixty is so insignificant a factor as to fall well down my list of considerations....if indeed I'd consider it at all.

Weight, however, is a different thing altogether!

Francesca

Francesca,
They're both very significant, but come into play in different ways. Weight matters most while climbing, as it takes more fuel to lift weight up a hill. Wind resistance matters everywhere, and becomes more significant with speed. Hold a ping pong paddle out the window at 20MPH flat to the wind and see if you can feel it. Do it again at 120, and you may get hurt. We cyclists know all about the effects of wind resistance and energy use. It is very significant at almost any speed and the largest drag bicyclist will experience. Heavy bicyclists know all about how weight effects climbing hills.
Slow driving will affect MPG always. Heavy vehicles hurt climbing.
Russ

[accrete]

Originally Posted by ruscal

...We cyclists know all about the effects of wind resistance and energy use. It is very significant at almost any speed and the largest drag bicyclist will experience...

: ) My answer to the problem while cycling...my home designed/spun front-wheel-drive leaning trike. Way fun, even if its never been wind-tunnel-tested.

http://www.accrete.com/p-tgl/hpv/index.htm



and my FWD bike : )



I may not go faster but i get ooohhhhsss and aaaahhhhssss from the passer-byers : )

[Francesca Knowles]

Originally Posted by ruscal

Francesca,
They're both very significant, but come into play in different ways. Weight matters most while climbing, as it takes more fuel to lift weight up a hill. Wind resistance matters everywhere, and becomes more significant with speed. Hold a ping pong paddle out the window at 20MPH flat to the wind and see if you can feel it. Do it again at 120, and you may get hurt. We cyclists know all about the effects of wind resistance and energy use. It is very significant at almost any speed and the largest drag bicyclist will experience. Heavy bicyclists know all about how weight effects climbing hills.
Slow driving will affect MPG always. Heavy vehicles hurt climbing.
Russ

Bicycling aside:

I was speaking to "aerodynamic shape" alone, and specifically within the limited sphere of camping trailers and the average speeds they travel at.

For decision-making purposes, at least for me, there's not enough variation in shapes among trailers to make significant differences in fuel efficiency, especially over the relatively small distances most travel.

Surface area presented to the wind is of course another story...

Francesca

[ruscal]

Aerodynamic shape alone could be most of the difference between my Jeep Wranglers 14-15 mpg and my girlfriends Jeep Grand Cherokees 19-20mpg when they are driven on the freeway. They both have the 4.0 six and similar tire sizes. I don't know the weight difference, but the freeways are pretty level around here, so not a big factor. The Wrangler was designed to block as much wind as possible. (Flat bumpers, grille, windshield, fenders, etc. It is also flat on the trailing edge. The Cherokee is a 2000 model with rounded swoopy everything. The front grille is rounded and sloped back. The headlights are sloped and faired into the body. The windshield slopes back radically, and the trailing surfaces are rounded as well. The frontal area of both vehicles could be slightly different as I had no way to really measure them. The rear axle ratios were identical and they both have overdrive. When driving in town stop and go the Grand’s mileage drops to about 16. The wranglers stays at 14-15. The shape has to be how the grand can achieve 33% better freeway economy. That is a pretty worthwhile difference unless you don't drive far enough to amass any real savings. The egg shape is a real advantage on fuel usage due to reduced frontal area and aerodynamics but eliminates some storage space inside a trailer.
Russ

[MC1]

Shape or weight or the size or shape of the TV??
It can get complicated.

Our Nissan van towing a 2,000lb Coleman pop up got us 19MPG av.

The same van towing 4,500lb Airstream averaged 16MPG.

Here is an interesting article that relates.... Can-Am RV :: HH 38-1

[Dave_L]

Originally Posted by Francesca Knowles

Bicycling aside:

I was speaking to "aerodynamic shape" alone, and specifically within the limited sphere of camping trailers and the average speeds they travel at.

For decision-making purposes, at least for me, there's not enough variation in shapes among trailers to make significant differences in fuel efficiency, especially over the relatively small distances most travel.

Surface area presented to the wind is of course another story...

Francesca

SA is a function of the 'shape', these are not mutually exclusive...

[cpaharley2008]

I was under the impression that when the new "towing" standards were published awhile back these also included "frontal area" requirements. Some auto manufacturers (Ford and Chevrolet) are using the FA numbers in calculating the capacity of their vehicle's towing. Known as the "Kite" effect, the calculations take into consideration of the trailer's frontal area and the impact on the tow vehicle. One trailer manufacturer, The Element, mentions meeting the the 60 s/f OEM limitations.
https://www.fleet.ford.com/showroom/...kchrtApr08.pdf

As far as weight, on the truck diesel forums it is all about the frontal area, NOT WEIGHT that impacts their calculations.