I posted this below but not much traffic there so if you don't mind there is my question:

I'd like to hear from owners that have a camper shell/topper on a F350 crew cab short box. I've done a couple of searches but didn't find any info. I'd like to know about the fuel mileage with the different toppers out there . I'm about to purchase a topper (SnugTop XTR) and would like to know if I will loose MPG and approx. how much ?
A. Topper that is flush with the top.
B. Topper that is taller by a couple of inches.
C. One of the taller toppers?

 

I don't think you are going to lose anything, I went from a steel cab height Gemtop to nothing then to a roll n lock tonneau cover and have never seen a difference. I had the Gemtop on for 3 1/2 years, nothing for about a year and now the roll n lock for about 5 months...mileage has always been around 18MPG hand calculated over 300K + miles.

These trucks have the aerodynamics of a bread box so unless you are thinking of a slide in camper on I doubt you will notice any difference

 

nope no difference in my short bed topper that is the same height as the cab. weighs aobut 200 or so if anything it rides "slightly" better.

 

I'll agree with that, my gem top was closer to 300lbs (ambulance doors)and it definitively made a difference in the ride as well as wet/snow traction.

 

Cool now to decide if I want to spend the $$ on the snug top I like the built in rack.

 

I had a mid height cap on my 2010 F250 CCSB and I did see a slight drop in fuel mileage, maybe 1mpg. I cant remember exactly what it was but I did see the change. I wouldn't worry about it. I'm getting the same cap for my new 11 F350 CCLB too. If you need the cap you need the cap, the fuel consumption probably isn't going to matter much.

On a side note, the reason I went with a mid height was for the head room. I am not sure what all you are wanting to do with the cap, or put inside, but I would think if you are hauling general stuff and packing the family for vaccations that the standard cab height would be more than enough space. In my case, any shell is WAY more space than I need but the other side of it is I will be using it as a camper too and want the extra head room A tall full height cap is overkill for my uses.

Just my 2 cents anyway, if its worth that.