Aerodynamics Matter !!
Hello All. First post here... wanted to share some data on aerodynamics. I am designing an ultralight (under 100 lbs/ft) small travel trailer and wanted to find out the effect of shape on aerodyna...
Forum Discussion
gmw photos wrote:93Cobra2771 wrote:
It has been shown that the Vnose trailers are actually WORSE than a flat nose camper for mpg. Why? Because of increased frontal area.
They are also inherently less stable while towing due to the turbulance the vnose creates. And cross winds make it even worse, again due to increase frontal area.
What a vnose does give you, though, is 3' of extra room over the tongue that a standard TT doesn't have. Which is nothing to sneeze at.
Ideally, a TT with a nicely rounded front cap, some side skirts, moon disk hubcaps, and some type of boat tail would be my dream.
A hard sided popup works really well due to low profile, but I'm not willing to give up all you have to give up to do that. :-)
One study I read about V-nose was that it increased turbulence down the sides of the trailer, which slightly increased drag. That was part of their theory about it yielding worse fuel mileage. The other thing I have wondered about with a V-nose is that it seems I often have travel days where I am pushing a frontal quartering wind. I wondered if a V-nose would then be presenting a "straight on flat surface" because of it's angle relative to the wind of that day. Pure speculation on my part.
Years ago, I bought a new Wells Cargo trailer that was our race trailer for the motorcycles. At the time, WC offered an optional fiberglass bubble nose they claimed was more aero. Their claim was "up to 10% better fuel mileage". It was something like $250 for it, and when I penciled it out, if it really would have got me the claimed 10%, it was going to be a fairly big number of miles just to pay back it's option cost. I passed on it.
Yep, when you put pencil to paper, you generally have to travel a LOT of miles to make the expensive mods worth their while.
The free or low cost mods are the ones that make more sense to do.
As I mentioned earlier, the easiest way to save mpg is to learn to drive it.
Case in point. I make a regular trip to myrtle beach once a year. If I really pay attention to my driving, and run 55-60mph, I can make that 500 mile trip with just over 11mpg. If I make the same trip staying right at 65mph, my mpg drops to just under 10mpg. It's all about how quickly I want to get the vacation started. That 5mph will get me there 30-45min earlier. :-)
