Camper shell and gas mileage?

[krooozn]

I am looking at picking up a camper shell for my 07 ST....I think it is fiberglass or at least it looks like it in the pictures. My question is this.....how adversely will the extra weight of the shell affect my mpg? I am thinking that it may balance out due to the shell cutting down on the wind drag of the open bed....seems logical to me....anyway.....any help/guidance is appreciated. I have got my truck giving me a consistent 19-21mpg with a combination of highway and stop and go driving....so really hoping that the shell won't hurt it too much...I really want the coverage on the truck.....

Thanx....Anita :scratch:

 

[JohnnyO]

My opinion is that the shell is a little more aerodynamic but that is offset by the extra weight, so it ends up being about the same.

 

[LONO100]

i have a shell that i put on mine during the winter months and the difference isnt noticeable. there is a rule saying that shedding 250 lbs of weight could increase your mpg by 1, so adding a camper shell that may just tip the scales at 100 lbs shouldnt make more of a difference than having a person or two riding with you.

as for the drag phenomenon in pick up trucks, ive also read that the drag created by an upright tailgate is just a myth, and that engineers make the height of the cabs of a pick up truck in relation to eliminating drag that would otherwise be created by an upright tailgate. after reading that, i experimented for myself and found that in fact it was a myth. at least for the two pick up trucks that i have owned.

 

[GreenMando]

My shell weights little more than the factory tonneau did.
I get 27 highway with a light foot, 22 if I am towing. I keep it down to 55 on the freeway and let a lot of people pass me.