ponygallery

I have a 01 2500 4x4 quad cab with 8' box and I usually pull a tow-behind travel trailer. I would like to know what kind of real milage gain anyone has had when adding a cab-high topper or a toneu cover. also, has anyone added AirTabs to the cab?
Thanks for the feedback

Machinos

Not sure about on a late-model diesel truck, but my old '78 D150 would get 2-3mpg better on the freeway with the topper on. That was with a slant six though, so I could actually FEEL the extra drag on the truck with the topper off, too...

Valv

I get approx 1mpg better with a tonneau cover.
As you probably know traveling with tailgate open does not help at all.

Deezel Nate

I think those air tabs are a crock of Editto be honest with you.

Fiftygrit

Ive got a cab high cap, i didnt notice any differance in towing mileage (30 ft TT) My mileage went up when I installed the XZT tow box, and its tolerable if I keep it between 60 and 65.

wmonroe

I towed and driven empty with and without my tonneau cover and haven't noticed any difference with or without it. Had a tonneau on the 97 also and same thing, same mileage with or without the cover.
Will

FiverBob

Look at the truck races - - they have studied drag and air flow a lot more than we will. They all have a slopped bed cover starting from the cab roof down to the back. A topper has been tested to show some improvement, but never have I seen any testing with toppers while towing a trailer. The tests also show leaving the tail gate down decreases mileage - - so, there goes the vented V tailgate for fivers. Again, I have never seen any tests towing a fiver with a vented tailgate or with tailgate down.

The street talk on cab roof wings for towing will have one guy gaining 5 mpg while another says all it does is move the bug line higher on the front of his fiver while reducing his mileage when not towing (obviously with the wing down in the stowed position). Overall the concensus seemed to be no gain with a wing.

Bob

HOHN

That's because you haven't studied aerodynamics.

They are based on valid science. This is NOT a turbo3000d type of product.

charger7022

i think myth busters touched on this and said you actual get better gas mileage with a open bed and tailgate up but a cap or cover is your best bet.

check out this link http://www.trucktrend.com/features/c...yth/index.html

ponygallery

Just a little follow-up. I do about 3500 miles a week and when I tow a 5th wheel I get better milage with the vent gate over the stock one. This could be from pointing the airfoow down and not at the front of the trailer.

taildragger

Empty with a "wedged" high cap, I got an increase of about 2mpg on the highway at 70-75mph