Made my first long trip(only 200 miles)since putting a roll up cover on my box and I averaged 14.8 mpg for the 200 mile trip, best I ever got before was right at 14. Was this just a result of the right combination of gas and driving or is this to be expected now?

 

I suspect this is mostly just a lucky combination of weather and road conditions.

 

I noticed zero change in mine after adding a cover on my truck but 50/50 of highway and in town driving.

 

Studies have shown the cover does offer a slight gain from reduced turbulence and wind resistance. I'd say it explains at least part of the .8 gain you got.

 

Either a tonneau cover or cab high topper, F150 or Super Duty, no improvements here.

 

I'm on my second Bakflip on my 2nd truck. First was a gasser and now the 6.7. I went for several thousand miles on the gasser going up and down I-95 for a few hunderd miles at a time, same route, multiple times, then got the cover. After a few more trips I did notice a uptick, not much but nothing else had changed so I'm a beliver.
Having said all that the biggest advantage is keeping stuff in the bed and out of the weather.

 

This has been discussed, over and over and over............

Gains may be there but its nothing worth noting, IMO.

Mythbusters did an episode on this theory.... The gains were found to be better with the tailgate up, and no cover. Out of all the scenarios.

I would NEVER encourage anyone to purchase a box cover for mileage gains. I just like mine to keep things out of the weather.

 

This is why I got mine. space is at a premium in a Reg cab and I finally got tired of having the cab cluttered with stuff that I didn't want exposed to the elements.

I really could care less about mileage, if I did I wouldn't have bought a SD. But I thought it was odd to see that big of an increase by just adding a cover.

 

Studies can show anything you want them to. Mine took a slight hit, less than 1mpg probably.

Consider the scales on a shark's skin. They create pockets of pressure differentials along the entire length of the shark which makes them swim faster (with less drag) than if they had smooth skin.

 

Well, at least your realistic in regards to owning a SD. Sometimes I wish I had a Reg Cab so I could actually use a different excuse of why I can't take extra passengers.

Instead of having to tell the truth to them, that I can't stand them, and wish they would leave me alone and find another ride. Then maybe so many people would stop calling me a Richard.

Ain't that the truth about studies.

In regards to the shark example, it is true. Mythbusters also golf balled the hell out of a vehicle (as in dimpling), and it reported better mpg's than with smooth surfaces. I just can't remember the exact gains.

So, if and when your vehicle gets hit by a massive hail storm, and after replacing all the broken glass, you cant look at the bright side knowing you will get increase mpg's from an act of God.....

 

I agree. Gains, if any are negligible at best. I use it to keep my stuff dry and out of sight.
As far as studies, I heard that 73% of all statistics are made up on the spot.

 

Right on!!!

 

Dont you guys read all the adds for aftermarket Desel parts? Each one adds 50 hp and 20% better fuel economy.
I actually over did it on my last truck. It got to a pain to stop and drain fuel out of it every 50 miles to keep the tank from over flowing as I drove.

 

Yeah, just like all the guys with 6.7's getting 27 MPG pulling 12,000 pounds up steep hills at 80 mph all day long. It makes me really sorry that I didn't spend the extra $9k for the diesel option.

 

a television show (????? Busters).. did a show in this subject.

last summer on a 2 way trip... South Carolina to North Carolina. and return....
running Empty. no cap or cover.

I averaged 19.5 going north doing 50'ish... heavy traffic but steady.
and I got 21.1 going south doing 55... speed limit most of the way...

but my 6.2L truck has 150,000 miles....
but towing my trailer .. I get 7.5 to 10. depends on the direction of the wind.