Tonneau cover MPG gains

Putting a cap, or tonneau cover on a truck might help fuel mileage slightly, but not 3-4 mpg. Somewhere less than 1 mpg is normal, and in some cases fuel mileage could be worse. It depends on a lot of factors.

Fuel mileage can vary a lot. I've seen 4 mpg over short distances, and 40 mpg over short distances. Until you've ran 2-3 tanks through the truck and calculated it by hand you're just guessing. And if you never did the same and calculated it by hand before adding the cover you don't have an accurate baseline to compare with.

 

I don’t know specifically about the tonneau cover, but the Mythbusters were wrong about a number of other things. They have an episode on whether a can of Coke can explode in a hot car. They couldn’t get it to happy even in the AZ desert heat. I’ve had it happen twice to me and it doesn’t even get that hot here. Most recently I had 3 cans in a 12 pack explode from heat (left them on the front seat while I was working). The result really sucked.

 

That must be one hell of a hill.

 

I was on my way back from a snowmobile trip in quebec an had a bunch of soda in cans stored in my enclosed trailer. It was about -20 when the trailer got a flat. H ad to pull off the shoulder of the road and get the spare inside the trailer. Inside was a mess, at least 1/2 dozen cans of soda exploded all over the sleds and gears requiring a good pressure wash to get the sticky mess cleaned up when back home.
Otherwise this whole mileage thing with the tonneau cover is getting deep. Gotta get my boots.

 

Tonneau cover will allow the flow of air over the cab to flow with less drag, simple physics.

 

Thats implying basically thats the same thing as driving with your tailgate down. Thats been proven bs for better fuel economy.

 

With the cover you will get less drag ..will you significant mpg ...probably not ..mpg depends on gas quality ..driving habit .Its like saying the cold air intake will give you better mpg and 5hp ...lol

 

Cap, cover, shell, or not, I think 27 mpg is awesome, like really awesome. Check back after a couple or 3 tank fulls, then you’ll have a good idea what you gained in mpgs.

 

lol instead of checking your physics book you need to check your fluid mechanics book, especially the chapter on laminar versus turbulent flows.

 

......I laminate my turbulent flows......

 

Call up and raise hell, yours must be broken..

 

The only thing my tonneau cover can do thats notable is make noise when you hit cross winds.

 

Complete sidetrack but whenever I hear the word laminar this is all I can think of.

 

My first day commuting 40 miles yielded 24.5 MGP.

1. Definitely less than the 27mpg it was reading on day 1 but still an impromptu over the 22mpg I was getting previously.

 

Temps also make a difference. My truck has been breaking back into the 20 MPG range now that it is warming up. 45 mile commute (90 round trip) at 70 MPH.

 

was it windy?

 

Yes and no. Like I said, it depends on a number of factors, such as cab configuration, wind speed, MPH, etc. With the tonneau cover, like with the tailgate down, drag is increased at the rear (depending on the factors I just listed) because of the way the air comes down onto the tailgate or tonneau cover. With no tonneau cover, the air swirls around in the bed and allows the majority of the air to pass over top. Manufacturers have added large lips onto tailgates to assist with the departure of the air as well. In my experience, however, I have found the difference to be negligible. Sometimes my MPG is better and sometimes it is worse. Too many other variables.

 

From google, so it must be true:

According to many experts, the best way to improve the truck's fuel economy is to add a tonneau cover. A tonneau cover will help reduce aerodynamic drag and can improve gas mileage by as much as 10%, see below for details.

 

To be fair, a lot of things come into play with cans exploding from heat or cold. We often have some explode from the cold, but it's rare that the entire pack explodes.

 

This.

My MPG took a HELL of a dive when the high was -20F. Now that we're in the 30's and above, the mileage is coming back up to where it should be.