JonU

Currently have a Leer fiberglass painted tonneau cover on my 2007 Supercab 6.6 bed, and tow a 23 ft travel trailer. Is there any benefit to upgrading to a truck cap aerodynamically? Setup tows great, just curious if it might help my mileage any when towing my brick of a TT.

dodgeman1

My guess is the distance from the back of the cap to the front of the trailer is big enough it won't help.

waltheraustin

There is studies that show the whole tailgate down thing doesn't help so I would guess that it wouldn't make a diff especially when towing

Simnut

Yup. They say air fills the box and creates a surface that the air goes over as it would with a tonneau cover. A canopy may create more air disturbance than a person wants..eddies or vortices between the truck and trailer because of the distance between the two as someone already mentioned. I don' t know...I'm not a fluidologist!

acdii

If you are thinking it will help MPG, it won't, trust me, because thats what I have on mine, and between the 14 and the 16 both get 7-9 MPG towing that huge wind sail behind it. The only thing that might help improve MPG would be a ramp like you see on semi's that directs the airflow over the top of the trailer. You would also need those rear flaps you see on trailers and the under belly deflectors to complete the setup and you might gain 1 or 2 MPG while towing. the only good thing about the topper and the reason I have them, you can store things back there out of the weather and lock it. I keep my genny, fuel, tools, cooler and spare propane in the bed, locked up and out of site.

dodgeman1

Ricktwuhk

No, and it would reduce your payload capacity even more.

Norotso

Since no one mentioned. You also have to factor in the cost of a cap vs. the longterm fuel savings if any...

JonU

I was concerned about the payload as well. Although the tonneau isn't light, I'm sure the cap is a good bit heavier. Not seeing weights on the Leer or A.R.E sights - perhaps too many variables w/all the various options.

Apples

Why not a larger version of aviation "flap gap" seals between the back of the bed/cap and trailer, and then one of those folding Chinese take-out box aero rigs and chassis skirts we see now on the back of semi trailers...

/ponder