Airstream Travel Trailer aerodynamics

[aerohead]

Well it looks like a few of us here at EcoModder will have to self-finance the free consumer information for the entire globe,just as we've been doing.
And I'm sure to make an absolutely fabulous contribution each year with my sub-poverty level pension income.
Dumpster-diving for cardboard and second-hand resin from Habitat for Humanity resale stores.Yeah,that 'll change the world alright.

[skyking]

I can attest to the smooth function of the torsion axles, our 1990 avion had them and it towed so much better than the current leaf sprung trailer.
My wife got a drink of water after we had secured for travel, and left the half full glass on the counter. We arrived home 100 miles later and I found it there, undisturbed. The next trailer will have torsion axles one way or another.

[slowmover]

Thanks again, Aerohead.

Numbers do go a long way towards explanation. It's difficult to explain to others that a premium aero trailer pays for itself in longer life, reduced operating cost, and all around safety when underway. It ain't just fuel mileage, nice as that is.

And a ten year old Airstream isn't old. A conventional TT is ready for the scrapyard at that point ( get out the moisture meter. Those numbers don't lie, either). One needn't spend a fortune in acquisition, nor in operation when an ordinary car can be spec'd to be a good daily driver and tow vehicle. The current assumption is that a pickup is the default choice. And it needn't be.

[aerohead]

Originally Posted by slowmover

Thanks again, Aerohead.

Numbers do go a long way towards explanation. It's difficult to explain to others that a premium aero trailer pays for itself in longer life, reduced operating cost, and all around safety when underway. It ain't just fuel mileage, nice as that is.

And a ten year old Airstream isn't old. A conventional TT is ready for the scrapyard at that point ( get out the moisture meter. Those numbers don't lie, either). One needn't spend a fortune in acquisition, nor in operation when an ordinary car can be spec'd to be a good daily driver and tow vehicle. The current assumption is that a pickup is the default choice. And it needn't be.

There's a website that does unofficial mpg testing of RVs when they ferry them to their facility.
They claim that a VW Jetta TDI pulling up to around a 19-ft Airstream can average like 38-mpg,compared to 50+ mpg solo.I'd be willing to downsize expectations to enjoy such efficiencies while towing.
Beluga Caviar vs cat food with the fuel savings! Adam Smith would give it the nod.

[slowmover]

Yes, I've seen claims of above 30-mpg from unimpeachable sources. But do not know details (travel speed, terrain, etc).

There are thousands of used Airstream trailers. For someone wanting to build a trailer, I'd strongly suggest rehabbing an old AS first. Will be done faster and better if original lay out is respected.

[MeteorGray]

I've got a '96 F250 automatic turbodiesel that I bought new 20 years ago for towing my travel trailer. At the time, I had a 27-foot 1967 Airstream, and with my new F250 was averaging 16 mpgs towing on the highway. However, when the Airstream began showing its wrinkles at 39 years of age, with its floor developing some soft spots and the frame needing some attention and etc, I finally got tired of the idea of putting more work into it, so I gave it to one of my kids for their starter rig.

I wanted something new for when I retired that I would not have to work on. I considered a new Airstream, but choked at the $50K cost to play. So I bought a new 28-foot Jayco for $17K that has torsion bar suspension and weighs less than the equivalent Airstream. While it tows just as well on the road, due to the unfavorable aerodynamic differential, I did lose about 1.5 mpgs (now averaging 14.4mpg). On the other hand, I saved $34K in purchase cost. Even though I didn't like to lose the mileage, I figure I got my Jayco for free because the Airstream would have depreciated by what I paid for the Jayco in the 10 years since I bought it, and the Jayco is still in excellent shape requiring no repairs so far as long as I am diligent watching to assure the roof keeps properly sealed.

My old Ford used to be among the leaders in towing fuel economy. Nowadays, there are new choices on the market, such as those diesel Mercedes and VW cars and SUVs and those half-ton diesel pickups which regularly are seeing 18 and 19 mpgs while towing travel trailers. It's true that those rigs aren't as heavy as mine, but their efficiency is nonetheless amazing. On the other hand, considering that I bought my F250 new for about $26K using 1996 dollars and the Jayco new for $17K in 2006 dollars, the newest rigs can't touch me for relatively low overall investment, even with their increased fuel economy on the road. But they sure are nice.

That's my story and I'm sticking to it.

[freebeard]

Well it looks like a few of us here at EcoModder will have to self-finance the free consumer information for the entire globe,just as we've been doing.
And I'm sure to make an absolutely fabulous contribution each year with my sub-poverty level pension income.
Dumpster-diving for cardboard and second-hand resin from Habitat for Humanity resale stores.Yeah,that 'll change the world alright.

Quoted For Truth. I hope I don't push that off the top of the page.

My story... 50-year-old 35' R-license park model located next to a Grocery Outlet, with 5¢/kWh electricity. I got it for $900 cash, with a membrane roof and an airconditioner. No TV so gas mileage is infinitude. Why would I want to go anywhere, when the whole world comes at me.

A thought... They make these beautiful polished and clear-anodized shells with a more pedestrian welded steel chassis; then separate them with a thin, 5/8" layer of something not much better than sliced lunch meat.

Suppose one got a salvagable shell and cross-braced the gutted interior like when you're chopping the top on a car, then lift it and substitute a layer of swing-door material—aluminum skinned plywood. On a sand blasted and POR-15'd frame.

I'd put a perforated Gurney flap all around the rear like the tail of a shuttlecock. Mostly within the wind shadow of the shell as a whole, it would slow the air close to the shell and pull the flow inward. In fact, that might be a field expedient fix for 1930s boat-tailing in general like the V-S V2.

[slowmover]

Having recently seen a few “I want to build an RV” threads (which takes years away from the object: going camping), figured I’d bump this back up.

HP demand.

On a typical RV day of travel (1968 or 2018) of around 300-350/miles, how much time is spent at that HP demand number? Five or six hours?

How many days per year as the average RV’er covers 5,000-miles? Fifteen?

I wouldn’t recommend fixating on those hours as the solution to less expensive vacation travel. As MeteorGray notes above, how much one has into the thing PLUS longevity, is more telling.

Airstream aerodynamics are such that pushing past them isn’t worth the effort.

The “less expensive“ route is an Airstream model that works great behind the family vehicle (most all of them). Is about ten years old so that depreciation is nil, and systems still close to new.

Both vehicles will spend 90% of their lives stationary. Reducing the number of stops (or cold starts from the campsite for a solo run) for supplies replenishment (water, ice, groceries, propane) NOT just tow vehicle fuel is how the game is played.

That’s the larger picture.

Next up is longevity. My vintage kin Silver Streak will be thirty years old next year. Looks close to new. Only now am having to replace some items and re-decorate. (Its contemporary square white plastic box travel trailers were tripped into the landfill years ago).

How long will you keep it?

(Let that question guide the rest).

.

[freebeard]

Here's what I was talking about then (from JACG a year later):


http://justacarguy.blogspot.com/2017/06/aspects-of-restoring-airstream.html

[Hersbird]

I think there is a way to make a modern airstream shape and style for much less that would perform just as well. I just wish a big company like Forest River or Jayco would try. The riveted aluminum is great but I think a SIP with a radius for the mid sections and molded endcaps. They kind of tried it with the Aviator but went off the deep end with cost and upgrades. I think there is something to be done somewhere between a $20,000 standard TT and a $75,000 Airstream.