Tonneau cover MPG

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nlambert182

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I was seeing 18.5 mixed driving before the tonneau, and still see about the same with it. Never really noticed any difference. I wonder if some folks subconsciously begin adjusting their driving habits with the idea that they're expecting better fuel economy.
 

zrock

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I seen better fuel econ when i had my truck cap on, when i switched over to a tonneau cover i noticed a slight decrease but never enough to worry about.
 

sblack33741

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Hey yall
I put a retractable tonneau cover from Truck2go on my 6.4 2500. I watched the TFL guys vid on their MPG test of cover on/off. They showed an increase of 2+ MPG. Well, I got same results!
While I didn’t take a dash pic of before I put it on, I reset my AVG and it was 14.5 mpg on my round trip commute of about 60 miles (28.5 in am, 28.5 in pm)… after I installed it, I reset again after the install and it was 17.3 mpg on same round trip! I wasn’t able to use cruise control due to Houston traffic, but I did try to drive in similar manor on both days. Not a bad improvement and it looks great!
It looks slick.
 

ECONORAM

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I looked at some wind tunnel data years back, as well as this Popular Science article. https://www.popsci.com/cars/article/2002-07/truck-drinks-less-car/
I've run both a tonneau cover and a topper. Both have helped mpg on my 07 1500 QC. The bed is 6'3"; i don't know if that's short or long. My best is 21-22 mpg at 70mph on the interstate. 24-25 mpg at 60mph if I will go that slow. However, the tonneau was a bit better than the topper if there were several stop and gos, 'cuz it weighs 200# more.
I could probably look up some trips from my pickup's early days, but one that sticks in my mind was getting 16.5mpg @ 65mph with less than 4k on the odometer.
Now at 176k it will see the figures above. True, I did add more than just a bed topper...

One proviso: all these figures are on 100% gas. Although I think I can match the 24-25mpg at 60mph by using E10 and Superchips Towing Tune. I'll maybe try that sometime.
 

Dave Haddon

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Logic would tend to suggest a smooth hard top cover would allow for a lower drag coefficient. I have also put. Skid plate under the front end to reduce turbulence under the truck.
 

turkeybird56

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I have full tonneau fiberglass top and color matched cover on my 5th Gen 2019 RAM. Cover improved mileage a lil but I also put heavier AT3W tires on truck which negated any gains. Next truck I will get a roll n lock cover but truck is sharp with full cover on.

Yes I lost bed for big stuff but I have a 14’ stock trailer for those items. IMG_1849.jpegIMG_0418.jpg
 
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tron67j

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I am always cautious about accepting gains in MPG without controlling for all variables. Everything from being a bit more cautious with acceleration (without realizing it) to knowing the same amount of gas used for test will impact the numbers. Using the onboard computer is also suspect, so much going on there. From 30 years of driving trucks with and without covers, I never noticed a bit of difference when I did check. Always 8' beds, maybe that makes a difference.
 

GTyankee

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My thinking ...
Without a cover & with the tailgate up, a bubble is formed
It will clean the paper out of the bed.

Another thing it does, the bubble actually helps to keep the rear of the truck more stable, the truck will not sway side to side as much.
The pressure on both inside & outside of the bed are close to equal.
 

Tray Burge

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My thinking ...
Without a cover & with the tailgate up, a bubble is formed
It will clean the paper out of the bed.

Another thing it does, the bubble actually helps to keep the rear of the truck more stable, the truck will not sway side to side as much.
The pressure on both inside & outside of the bed are close to equal.
A man that looks at the positive side of things, I like that!
 
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