Which RV have the best aerodynamics? A, B or C?

canadiankid wrote:
If trailer companies wanted to make a more aerodynamic shape they would be better to round the back of the trailer. Most people don't understand that putting the air back together is more important than how you rip it apart.

The most accurate answer,there is so much more to consider,but it is amazing how many of the units now have an absolutely flat and square back,cheaper to make and that is all that matters now.

Agree with Dick B. No trailer is worth having if it isn't laid out to suit your needs.

Big Katuna wrote:
Doesn't matter much; its about frontal area and they are all rolling bill boards. Weight is more crucial and HP. More HP used equals more $$$.

Important question is
"Can you afford an RV?'

Fuel consumption is not the most expensive part of RVing.

Weight has very litte to do with it. It's mainly in the frontal area. I can pull an empty fertilizer spreader or a full one (with 4.25 tons in it) and the mpg difference between the two is less than 1mpg difference.

You can find "v" shaped trailers here, I am just not convinced that they help that much.

http://www.forestriverinc.com/TravelTrailers/VcrossClassic/default.aspx

The best is a round nose and a long tapering tail. Thus, why they put a round nose on tankers under the water line and why submarines have a round nose also. If you can't have a long tapering tail it's best to just cut it off sharply. At least that's what my old fluid dynamics book said. I'd guess "C" is closest to a round nose.

Jayco changed their profile on the Jay Flights

My 2008


My 2012

I say not much difference at all for mileage, but interior space is definitely affected by a steep slope ceiling or a gradual slope ceiling.

I agree, all three will be about the same. I have an Airstream and used to pull a 21 ft hybrid. I now tow a 26 ft that is 2000 pounds heavier. I get the same mileage now as I did before with the white brick.

The comments about "putting the air back together" are right on. I have towed this thing over 25K miles and averaged just over 12mpg. A couple of years ago I put a bike rack on the back of the trailer and now am getting just over 11mpg. I lost a mile per gallon because of the disruption to the air flow at the back.

I also agree with the poster who said this shouldn't be a big issue for anyone unless that is all they do is tow their trailer down the road. There are lots of other things to consider, like floor plans and such.

Theoretically C would have the best aerodynamics, but the truth is you'll need a lab and the difference will only exist on paper. The most aerodynamic shape would closely resemble a double edged needle. You're gently separating the air over a longer length and gently allowing that air to return to its original state. This allows for a less turbulent airflow which means less drag. Trailers are no where near this shape. A conventional, v-nose, or rounded front cap is still a very large object being pulled through the air. Front caps are only a small part of the equation. The flat rear of the trailer has just as much impact as the front cap. The flat surface and sharp edges causes an instant void which air rushes in to fill. That rush of air creates drag. Airstreams does a better job since their caps are more rounded, but they're not the end all be all of efficiency. There's also 3 other areas on trailers that have impact that people forget about: the roof, undercarriage, and protrusions. Until we see some radical changes in the aerodynamic engineering of these trailers, they're all essentially bricks being pulled behind vehicles. It would be best to focus on floorplans and find what makes you happy.

Rockhillmanor mentioned air deflectors, but they aren't really that effective in the real world. The deflector has to be placed fairly close to the trailer and angled properly or the airflow will dip between gap the tow vehicle and trailer making it ineffective. In most cases it's not possible to get close enough due to the tongue length. If you were able to get the deflector dialed in perfectly, it would still only addresses one direction of airflow to the trailer. Air still enters the trailer gap from the sides and under the tow vehicle.

They all have very close to the same frontal area, even Airstream. More importantly, they all have the same square back, which the Airstream is slightly better, thus the slightly better fuel economy owners report.

Budget 8mpg if pulling any of those with a gas engine. You'll be happier if you get 9mpg than if you budget for 10mpg and get 9mpg.

You are about to invest $15-25k for something new. If you tow weekends at 2500 miles per year, the fuel cost is difference between 11mpg that is unlikely for any of them vs. 8mpg is $300. There are far more important things to consider when choosing an RV for your uses.

Also, the tow vehicle makes a difference. A full size van would be different than a long bed PU with no cap on as the wind can drop back down and hit a larger portion of the trailer front.

As others have said, unless you are joining the carney circuit putting 50k miles per year on the rig, it's a pointless discussion from a financial perspective.