i just got my 2006 dodge 3500 dually and drove from atlanta Ga to lawton oklahoma for the ice storm pulling a 16 foot dual axle enclosed trailer with a few chainsaws in it.

anyway it was about 1000 miles and i drove around 65 to 70 mph the majority of the way and got around 12.5 to 13 mpg.

i thought i would get at least 15mpg. I mean especially with an empty trailer

the truck is completely stock with 30 or 31" tires and i believe 3.73 gears

and actually i think it has some sort of aftermarket muffler...its short and really fat. maybe its not a muffler, maybe a cat?

 

A empty or loaded 16 foot enclosed trailer is a big wind sail. I have a 28 foot enclosed trailer that is 8'6" wide and 8" tall above the frame. I get about 12 to 13 empty and 11 to 12 loaded with 8000 lbs.+ Try a flatbed empty. I only loose a MPG when empty,Loaded is another story.......

 

yeah i was almost positive it was becuz of it bein enclosed...

Thank God its not my trailer, lol...i have an open trailer.

 

You surely would have gotten the numbers you were looking for if you had slowed down to between 60-65 mph....

 

yeah but goin 60 mph for 900 miles would take forever...i woulda like to have gone 80mph the whole way

i actually did get good mpg's for 125 miles cuz the hwy was solid ice from memphis tn to little rock arkasas and i had to drive 25 mph

 

Pulling my travel trailer, best my truck gets is 13.5 mpg.
Flat ground, no wind and driving like you have forever to get nowhere, maybe 15mpg is possible.

 

i am think maybe a slightly bigger tire intake, exhaust, and a smarty may help...yeah?

 

You throw all the mods you want at your truck & in the end you will still have that great big parachute behind you. Towing an enclosed trailer is a thirsty endevor. Get used to it & slow down if you want better economy.

And just to do the math for you 900 miles at 70 mph is 12.9 hours of driving while 900 miles at 60 mph is 15 hours. The trip would take 2 extra hours. Hardly the FOREVER you described.

 

That would be normal for my 06 Dually.

 

My 05 gets 17 towing a 3200 lb racecar on an open 18' trailer. All the guys in gas engines get so ****** when we talk about it. Plus when we are sailing down the highway it doesn't even feel like there's a racecar being towed. truck does great. By the way I have 410 gears.

 

I can do that to with my racecar on my 18' open trailer.

Now throw that same car in the 26' enclosed & watch the fuel economy drop by 4 mpg MINIMUM.

The biggest problem with the enclosed is the wind drag....no way around it.

 

Guess I'm the only one that thinks thats a little low. When I pulled my 16' dual axle enclosed loaded to about 6.5k I got anywhere from 11-13 mpg at those same speeds. And I have 33.5" mud terrains. If the load makes that little of a difference that surprises me.

 

I get 12 city 15mpg highway unloaded with no trailer, hard bed cover going 65. Put a trailer on it of any size and were talking single digits.,....I think you are ok!~

 

Do Truck bed campers make a big diff in mpg's

 

Sure. They add weight and additional drag. The taller (bigger) the camper, the worse it gets.

I see about a 2-4 mpg drop with a slide in (pop-up style) camper. When I get to my destination, I unlatch the 4 corners and crank up an additional 16" of headroom. There is no bathroom on my camper, and only 20 gallons of fresh water. The bigger campers (with hard sides, slide-outs, and bathrooms that require grey and blackwater holding tanks) can affect mileage by 4-8 mpg.

The faster you drive, the bigger the effect...