Myths and misconceptions

It’s a quiet time for us, relaxing at home base in the holiday season.  We have no plans to take the Airstream anywhere until after Christmas, which means we will have spent a full five weeks here in the house.  In the hiatus, since we have no Airstream adventures to relate, I want to use a few blog entries to talk about questions that I am often asked when we are traveling.

The reason for doing this is simply that I am constantly reminded of how much misinformation exists on the Internet about RV’ing. Online forums filled with urban myths, badly-researched or biased magazine articles published by people who should know better, and poorly-edited books from “RV experts” are the primary sources of misinformation that new RV’ers come to believe.  It’s a travesty. Most people don’t understand the most basic concepts of trailer hitching, for example, even though incorrect hitching can result in their death.  Many RV dealers are complicit in this as well, by the common practice of just shoving a new trailer owner out the door with minimal instruction.

When I was learning to fly airplanes, I was impressed at how safety-oriented the industry was.  Everything in aviation is ultimately about safety, which is why it has an incredibly impressive statistical record. As a member of the Airline Owners and Pilot’s Association (AOPA), I received a glossy monthly magazine (AOPA Pilot) which was extremely well produced and loaded with useful information. My parents (also private pilots) subscribed to a newsletter by Belvoir Publications which analyzed the causes of aircraft accidents, which they passed on to my oldest brother (another pilot) and me.  We read it like our lives depended on it — because they did.

In aviation, pilots in training are often expected to read a book from the 1940’s, called “Stick and Rudder.”  In that book, author Wolfgang Langewiesche precisely described what happens when a pilot controls an airplane, in a way that defuses misconceptions that would otherwise occur among pilots.  It was a seminal work, so important that it remains in print today.  There is no comparable book on towing in the RV industry, which is why I asked Andy Thomson to begin writing articles for Airstream Life on that subject.  We hope that someday Andy’s articles will be recompiled into a book much like “Stick and Rudder,” which I will publish.

No question, part of the reason that there is so much good information for aviators compared to the dearth of good information for RV’ers, is the fact that aviation is a very high-profile and wealthy industry. Despite the fact that there a new Airstream runs $35,000-100,000 dollars (about the same price range as a new Mercedes) and that there are hundreds of million-dollar Prevost buses on the road, RV’ing is still too often viewed as the domain of country bumpkins and “trailer trash.”  The industry sells itself short.  When we were learning new concepts in aviation, like Instrument Flight, we considered it a good investment to buy a series of King videos for $80. We watched so many videos of John and Martha King in the living room that it felt like they were members of the family. But even if you are willing to spend in order to learn RV’ing concepts, where do you look for trustworthy information? Too much of what’s out there is either unreliable, or produced by “interested parties” with significant bias.

That’s probably why I’ve been increasing the educational aspect of everything I can touch.  Last year’s Alumapalooza included seminars on towing, axles/brakes, and maintenance.  We’ll do the same again in 2011.   I’m also working on a book of my own for new Airstream owners, which I expect to publish in the first half of 2011.

Andy’s book probably will take a couple of years to complete, but when it comes out I expect it to be an important and long-lasting work.  If you haven’t seen his towing series in Airstream Life, it’s worth the price of subscription all by itself.  (We have some of the back issues in the online store.)

Now, you may be thinking, “Come on — towing is just driving. It’s not nearly as complicated as flying.”  To a certain extent that’s true, but if you can die because you didn’t understand a basic principle, isn’t it worth learning more? I really hate it when I run into long-time RV’ers who say, “We’ve been doing this for XX years, there’s nothing anyone can tell us that we don’t already know.”  Baloney.  I find those are the folks who are most often full of misconceptions and half-truths, and are anxious to spread them around like a virus.

Here’s a really simple example.  How many times have you heard that reducing weight in your trailer will improve your towing fuel economy?  Like a lot of things, there’s some truth to that, but not nearly what people think.  Sure, lowering the trailer weight will result in less energy needed to get the trailer moving from a stop, or pull it up a hill.  But RV’ers spend most of their fuel budget pushing air out of the way, not pulling away from STOP signs.  Aerodynamics play a much larger role in fuel economy than weight.

The misconception about the impact of weight has led to the popular myth that you can save fuel by not carrying water in your fresh water tank.  It’s nonsense, but it is continually spread even by experienced trailerites.  I recently read a book by an Airstreamer who had bought into the myth that reducing his trailer’s weight by dumping his water supply would improve his fuel economy.  So, one windy day on the Interstate he dumped his water, and lo-and-behold his fuel economy did increase that day.

What really happened?  Most likely, the wind decreased slightly, or he reduced his speed a little.  The reduction of weight caused by the loss of 20 or 30 gallons of water, when traveling on the Interstate, is not going to result in significant fuel economy improvement.  If you don’t believe it, then consider this:  Does your fuel economy change materially if you add one passenger to your vehicle?  Probably not unless you strap him to the roof, where he can block some of the windstream.

I had a radical example of the importance of aerodynamics vs. weight last December, when I was towing my 17-foot Airstream Caravel from Michigan to Arizona with a diesel tow vehicle.  Along that 2,000 mile route, I averaged 13 MPG, which is about the same that I get towing the big 30-foot Airstream Safari. But the Caravel weighs just 2,500 pounds, while the Safari weighs about 7,500 pounds.  Triple the weight, almost double the length — and yet, about the same fuel economy.  If a 5,000 pound difference didn’t affect my fuel economy, why would a 160 pound difference (the weight of 20 gallons of water)?

The reason for the similar fuel economy lies in the fact that both Airstream trailers have approximately the same frontal area to pull through the air.  The Caravel is a foot narrower, but that doesn’t make much difference.  In either case, you’re still pulling a rounded block face measuring about 60-70 square feet through the air at highway speed, and that takes a heck of a lot of energy.

winnebago-1966.jpgLook at the boxy Winnebago pictured at left.  The fuel economy of those things at highway speeds is horrible, about 6 MPG on a good day.  Would you make an airplane that looked like that?  It looks like an origami project.  All the folds, flat faces, and square corners add up to incredible amounts of aerodynamic drag. Adding a couple of hundred pounds to that aerodynamic disaster wouldn’t be noticed in terms of fuel consumption.

Airstreams are inherently much more “slippery” than most other travel trailer designs, so we get better fuel economy overall.  Airstream claims about 20% better, which I can believe based on many conversations I’ve had with owners of other brands.  But it could be better.  Even an Airstream has lots of drag-inducing objects hanging off which reduce fuel economy, such as awning, air conditioner, door handle, etc.  When the economic justification is there (higher fuel prices), you’ll see more radical designs of travel trailers and motorhomes that eliminate the bulges and junk on the outside.

The industry is of course interested in reducing weight too, but that’s mostly a response to small tow vehicles with lower overall towing capacity.  The real fuel economy savings will come when travel trailers slip through the air with less drag.

This example of the “weight myth” is just one of dozens that permeate the RV space.  You’re not going to die if you don’t understand it, but there are other myths and misconceptions that are more dangerous, or which cause people to waste their money.  When I’ve spotted them in the past, I’ve talked about them, but perhaps not enough.  I think my tolerance for the “industry standard” level of ignorance and banality has begun to fade, so in the future I’ll call ’em as I see them.


  1. Tom says

    Good post Rich. As another data point, using my 2005 Honda Odyssey – my average fuel economy hasn’t changed from towing my 1900 lb T@B teardrop to towing my 3200lb (wet) Argosy Minuet. The rounded Argosy is more aerodynamic than the T@B was. Even taking into account pulling the heavier Argosy up hills, it gets the same fuel economy.

    Also to your point – speed and wind plays a mighty big role too. Towing that T@B cross-country managed anything from 16 mpg (65 mph, flat Ohio highway) to 11 mpg (South Dakota and Montana, windy plains, 75mph).

  2. says

    “The misconception about the impact of weight has led to the popular myth that you can save fuel by not carrying water in your fresh water tank. It’s nonsense…”

    Does that mean Emma no longer has a limit to the number of rocks she can collect?

  3. says

    Great post, Rich. Count on me to help any way I can.

    Gosh, can you immediately tackle portable generator grounding, Goodyear ST tires, breakaway cable length, propane refrigeration on highways, venting of interior space (especially with catalytic heaters), and maximum towing speeds?

    Just kidding, but some of my favorite targets. I’m all for the frankness and believe you will be the great moderator for separating myth from reality.

    I look forward to seeing this develop. Thanks for putting the re-information (as opposed to mis-information) on the table.

  4. insightout says

    OOooo, Leigh, that hurts. Parental criticism cuts deeply, but the Maze Man does have a good record as a Dad.

    And why no A/S Life watermark on the photo of the beautiful Winnebago Brave ?

  5. Terry says

    Rich, I have tried telling people that 30 or so gallons of water does almost squat as far as fuel economy, but their minds are made up, I can’t convince them of the facts. Too bad there isn’t a published chart that shows how little a tank of water affects mileage. Even my boss is a disbeliever.

    Something else, when you fill the tank below the frame with water, you help the trailer tow better, since the weight of the water helps lower the center of gravity of the trailer.

  6. says

    Leigh: Nice try! I can see whose side you are on! The rock limit stands only because if we don’t put a limit on it we’ll end up with enough rocks to break our axles.

    Dr. C: No watermark because I swiped that photo. Yeah, yeah, sue me.

  7. says

    Excellent post.

    I’m used to dealing with this same problem daily in the service dog world, only on stuff lots worse than this (see my latest skunk post for the epitome of that one) because of the feelgood factor which isn’t in play here. Drives me nuts, and I always try to take the same approach you are – educate.

    This specific MPG discussion used to go on at the B forum all the time, and ended up the same way as what you’ve described. Normally consisted of perfectly friendly discussions (as opposed to the kinda stuff you’re talking about) where people putting a lotta miles on theirs on long drives would just try different stuff to see the actual effect on gas mileage. End result was always that the mileage really depended on how fast they drove (i.e., how much air are you trying to move outta your way and at what speed), and they would arrive at the optimal time spent / distance traveled vs gas used speed for them, usually in the range of +- 5MPH from 60.