robctc wrote:So I don't have a ton of experience towing and haven't started my CTC build yet, but I am the kind of person that researches for literal days, and as a result bought a flat nose trailer after reading many forum posts and other internet commentary from old curmudgeons with decades of road experience.
So heres what I found, summarized (hopefully) with simple explanations.
- Those air tabs DO make a difference, but the worth is more in preventing trailer sway and feeling more stable by breaking the suction at the back. Don't expect more than 1 MPG difference, do expect to stop feeling the sway when a semi passes.
- V-noses don't actually help aerodynamics, though many swear they do. If your vehicle was pushing the V-nose, it would help, but the air is already broken by the front of your vehicle. What happens instead is that there's more surface area on a V-nose for wind to hit both those sides, and add to sway. However, this is a difference you could see in a wind tunnel. The average person could pull both and probably not notice. If there is a MPG difference between the two it couldn't be more than 1-1.5 MPG.
- Those nose cones DO help, but you're probably better off with a DIY solution. 1-2 MPG difference but commercially they're around $700, so the math doesn't work out well.
Other things to consider doing:
- Insulate the underside of your trailer to the bottom of the supports. Air moves down there too, so the less pockets for air the better.
- Get the top of your vehicle level with the trailer. Personally, I'm going to add a rooftop carrier to my SUV because right now the trailer sits a good foot higher, and thats a big sail.
- Distribute the weight inside evenly. Thats just trailer 101.
So if you do all the things I wouldn't expect more than a 3-4 MPG increase, and that will vary per driver and vehicle. Doing all those WILL do a lot for trailer sway and safety, which arguable is worth way more than an extra stop at the pump.
Hope this helps, but take it all with a grain of salt because its just research.
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Pretty much sums it up.
The nose cone needs to be a sphere like the commercially produced. Build a mold, make one out of fibergrass, attach to trailer.
Put the angle flaps on the rear of the trailer like tractor trailers use.
Soften the wheel wells and include covers over the wheels to enhance air flow.
I gained 1 mpg by putting kayaks on roof of tv changing the air flow.
Go to the ecomodder forum. Lots of discussions about trailer design, air coefficients, etc.
https://ecomodder.com/forumIt was interesting to learn that the flat back of a cargo trailer is more efficient than the teardrop trailer. But can still be improved.