Round vs Squarish Eggs

[Bruce H]

I convinced myself that I want one of these for my truck. http://www.fibrobec.com/quattro-caps/index.html
It is the tallest camper shell that I can find. I was thinking it would divert some of the air over the top of my trailer when towing. Like the airfoil on a tractor trailer truck. Plus I take an ATV with me when I travel and this is the only one that has a large enough opening to accommodate one.

The problem for me is it is manufactured in Quebec and there is a very limited dealer network in the U S plus they are all in the Northeast. I have no immediate plans to travel in that direction. Last year I called two U S dealers and a Canadian dealer and got widely varying prices. It looks like I would be out well over a thousand dollars in transportation costs.

[Greg H]

Have you checked some American manufacturers?

[Bruce H]

Originally Posted by Greg H

Have you checked some American manufacturers?

Yes. I did extensive searchs a couple of years ago. Some of them make one that looks similar but none of them had enough rear door clearance to load an ATV. Plus the taller that back end is the more airfoil effect it should provide for the trailer.

[Francesca Knowles]

Originally Posted by melissab

With e'body watching their MPG's, I was wondering if anybody has towed both a round egg and a squarer (is that a word??) egg and can report on the MPG differences? In particular I was thinking of the Scamp/Bolers compared to the Trilliums/Escapes. I'd think the squarer FG rigs would fare worse. So is there a difference between the 2 shapes and gas mileage? And if not, why not?

Hi, Melissa

The differences in mileage are infinitesimally small compared to the differences in the workability of the inside space.
I've owned both shapes, and the extra few inches of the interior of the "squarer" trailer is huge in terms of usability.
You might want to check out the current thread on one of the rounder shapes at http://www.fiberglassrv.com/forums/f...tml#post249214
It's one thing to "get there", and another to be comfortable when you do!

Francesca

[honda03842]

I wish comfortable was proportional to square footage. So many of my neighbors should be so much happier. So many people today have rooms in their homes that they do not enter once a week, yet stressfully work to make their mortgages, rarely stopping to enjoy the beauty of our world.

Last year we were in a campground talking with a couple of RVers. The wife was complaining about the size of her 5th wheel's kitchen. She invited us to see it.

Seriously her kitchen, with center island, was bigger than our trailer. We smiled and invited her to our trailer. Now she says she'll never complain again and yet we are totally happy with our kitchen area.

We are in the process of cleaning out our Motorhome, getting ready to sell it. Though we thought we had downsized when we moved into it some years ago, it's obvious that we had too much room and too much stuff.

You learn to operate in the space you have. My niece traveled Europe for a couple of months living out of her backpack and was joyful. We always feel so fortunate to be doing what we do, are happy to have a clean shirt and a fresh pair of jeans. It's enough.

It's interesting to me, and I've only learned this over the last ten years of RVing, how little the joyful soul needs to be satisfied. Square or round, interesting but not the critical component.

We are now working to maximize the space in our Scamp 16. It turns out there's really ton's of unused space in that volume and will easily meet our needs.

Safe and joyful travel to all,

Norm

[Roy in TO]

I know that Thom from TrilliumRV delivers his trailers up to Canada and out east a few times a year. He usually travels back empty. Might be worth a try.

[Francesca Knowles]

Originally Posted by Tony Nowak

We get about 3 less MPG with the Bigfoot versus the Scamp, of course the BF is 130% heavier, but as Dave comments the frontal area is a killer.
We lockout overdrive on the Ford 150 (4 speed auto) when using the BF.
Tony

Hi, Tony

I think this is BOTH a grammar and a math question!
By "130% heavier" do you mean that the Bigfoot is twice plus an extra 30% the Scamp's weight?
Or that it's the Scamp weight plus 30%?
If the first interpretation of your meaning is the correct one, I'm surprised that you're only getting 3 mpg less with the heavier trailer.

Francesca

[honda03842]

Originally Posted by Francesca Knowles

Hi, Tony

I think this is BOTH a grammar and a math question!
By "130% heavier" do you mean that the Bigfoot is twice plus an extra 30% the Scamp's weight?
Or that it's the Scamp weight plus 30%?
If the first interpretation of your meaning is the correct one, I'm surprised that you're only getting 3 mpg less with the heavier trailer.

Francesca

Francesca,

In towing a 25% heavier trailer this year, the Casita 16, I had better mileage than towing our Sunline 15.5. In mostly non stop and go driving on relatively flat roads I think the shape/frontal area is more important than the weight. I got 3 mpg better mileage (23 versus 20) towing the Casita.

In these discussions it helps if the actual mpg is listed versus the difference.

By the way what do you tow with?

Norm

[Bruce H]

I believe that it is not the weight that kills fuel economy so much as the extra drag caused by aerodynamics. For example, I am sure you could load 3,000 lbs of cement bags in the bed of a pickup truck and it would have little effect on fuel economy because it would all be down in the bed of the pickup and not catching any wind. But, if instead of cement, you hook onto a 3,000 lb trailer you will see a definite reduction in fuel economy because of the extra drag created by wind and additional wheels and tires.

[Bruce H]

Here is another extreme example: In 2007 I bought a new Ford F-350 with a gas V8. I had it about three days when my brother called. He had bought a corvette over the internet in Eastern Kentucky. He had a large enclosed trailer and was going to go get it. He ask if I would go and help drive. I told him I had a new truck that I needed to break in and if he would buy the gas we could take my truck. We hooked onto the trailer pictured and pulled it 1000 miles in 24 hours. That trailer was NOT aerodynamic. That huge flat front caught wind like a sail. The truck had a six speed manual transmission. We never got into overdrive. The average speed was about sixty mph. On a level road with no wind that was about all it would do. It got 8 mpg on that trip.

[melissab]

So the general agreement seems to be shape matters more than weight. So a 3000lb Egg shaped Trailer would do better on gas than a 3000lb Trillium/Escape etc even though they are both fiberglass.

[Francesca Knowles]

Hi, Norm

My TV is a '97 Kia Sportage 4cyl 4x4.
I get your point about your 25% heavier Casita- I'm just wondering if that's what Tony means, too!


Francesca

[Alf S.]

Hi: Bruce H... What A Drag!!! Aerodynamics is why I like our Escape 5.0!!! Here's a pic of our former TV& Trailer on the road... and the new tug is only 2" shorter in height.
Alf S. North shore of Lake Erie

[honda03842]

Originally Posted by Francesca Knowles

Hi, Norm

My TV is a '97 Kia Sportage 4cyl 4x4.
I get your point about your 25% heavier Casita- I'm just wondering if that's what Tony means, too!


Francesca

Francesca,

What does a Trillium 4500 weigh and what kind of mileage do you get towing and not towing?

Thank you,

Norm

[aimeelightsey]

I asked a friend who is an engineer and he says the same thing. Shape matters more than weight since weight is has the greatest effect during acceleration/climbing. So due to inertia it has periods of more or less impact on energy cost.

However, wind drag always has some impact. He says that cars have a non-aerodynamic design. Optimum shape is like a teardrop -- round front and tapered rear. I told him about the Lil Snoozy's and he said that was the exact reverse of an aerodynamic shape.

[Francesca Knowles]

Originally Posted by Tony Nowak

We get about 3 less MPG with the Bigfoot versus the Scamp, of course the BF is 130% heavier, but as Dave comments the frontal area is a killer.
We lockout overdrive on the Ford 150 (4 speed auto) when using the BF.
Tony

I'm still trying to understand Tony's results above.
He says that the Bigfoot is "130% heavier".
I don't know the Scamp's weight, but for ease of calculations, let's pretend it weighs 2,000 lbs.
"130% heavier" means that the Bigfoot weighs 4600 lbs m/l.
Is it the findings of the group that the extra 2600 lbs is a measurably less important factor than trailer shape when it comes to gas mileage???

Francesca

[Mike Magee]

Generally speaking, I think that's a valid assumption. Another example: my gas mileage towing my cargo trailer does not vary significantly between unloaded and loaded (with about 1800 lbs). The mileage change between 65 mph and 55 mph is about 2 mpg, however. Wind resistance is the key.

[Francesca Knowles]

Hi, Mike,

That IS very interesting...
I've always thought my mileage worse when I'm traveling all loaded up with passengers, extra tanks, etc. than when I'm out on my own.
I'm going to have to pay closer attention this year!
In your opinion, are the rounded edges more important than overall width, height, etc.?
And how "round" should they be to realize measurable gains?

Thanks

Francesca

[Andrew GPSMapNut]

Originally Posted by Francesca Knowles

I'm still trying to understand Tony's results above.
He says that the Bigfoot is "130% heavier".
I don't know the Scamp's weight, but for ease of calculations, let's pretend it weighs 2,000 lbs.
"130% heavier" means that the Bigfoot weighs 4600 lbs m/l.
Is it the findings of the group that the extra 2600 lbs is a measurably less important factor than trailer shape when it comes to gas mileage???

Francesca

Running on a flat highway that extra 2600 lbs will not matter much.
IN hilly terrain or stop and go traffic that extra will eat gas and brakes - engine breaking may often be not enough.

At highway speeds, trailer / TV shape / wind resistance will play significant role in gas mileage.

[Francesca Knowles]

Is cutting wind resistance the purpose of the V-nose design I see on some cargo trailers?
That would be an interesting modification to contemplate for my Trillium...

Francesca