Ford air tunnel testing: tailgate myth and tonneau cover (aerodynamics / MPG)

[Thoron99]

Interesting. I saw this topic and watched the video while at work today, then driving home there were a few leaves in the bed and I noticed in the rear view mirror they were swirling around back to front in the 'air bubble' that forms in the bed. Most of them stayed in even on the highway stretch.

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[lajlmt]

Im a visual guy so this video helped me. I hope it helps others.

There’s work to be done wait I’m retired. I’m just using this as a hobby. Glad I got the tonneau cover though!

 

[Barracuda340]

Tonneau cover looks cool. That's good enough for me.

 

[Guv]

One look at a NASCAR truck should tell the story about covering the bed. Now a spoiler is added for downforce which will add an amount of drag depending on the actual size.

 

[Hoagus]

A lot of independent testing has been done and the number that seems consistent is 7, 7% improvement in mpg over no cover. That's a 2 mpg gain on my Maverick not to mention the other benefits.

Sources for this? Seems quite high.

 

[Hoagus]

One look at a NASCAR truck should tell the story about covering the bed. Now a spoiler is added for downforce which will add an amount of drag depending on the actual size.

Most of us don’t drive at nascar speeds, so it’s not really relevant.

 

[surfstar]

Sources for this? Seems quite high.

I'd wager its more likely a 7.7% improvement to drag and not 7.7% direct mpg improvement.

 

[MakinDoForNow]

I'd wager its more likely a 7.7% improvement to drag and not 7.7% direct mpg improvement.

Not that it matters much but I read it as 7.( blank)7%(being start of another sentence as in "7. 7% not 7.7%".

 

[Guv]

Most of us don’t drive at nascar speeds, so it’s not really relevant.

Bull shit, air flow is air flow.

 

[RichardCranium]

Just some math, for fun a 2mpg improvement as reported by several on this post is roughly 5% at 40mpg average (less if you are getting more)
At 40mpg, a 2 mpg increase saves 1 gallon of gas per 20 gallons or 1 gallon of gas for every 800 miles.
this translate to 10 gallons of gas for 8,000 miles, 100 gallons for 80,000 miles, 200 gallons for 160,000 miles.
so, if you drive your truck for 80,000 miles, you would multiply 100 times your average gas price (move the decimal 2 places) so $3.599 gas saves you $359.90 per 80,000 miles. We can also do the division to find how much money you can save per mile, which in this case would be your price per gallon of gas divided by 800. 3.599/800=0.0045 which is a 0.45 cents per mile savings at $3.599 per gallon of gas. To find break even mileage, divide the final cost of your cover by .0045 and that will give you your break even mileage. $450 cover would break even at 100,000 miles.

 

[caa60126]

[

Im a visual guy so this video helped me. I hope it helps others.

very true. For the most part

Hood length
Cab height/length
Drop distance from top of cab to bed/tonneau cover
Bed length
Tail gate up/down

all combination for mpg negligible with a Mav

But with all this said I wouldn’t drive a pickup with the tailgate down unless cargo dictates.
Your mileage may vary.

 

[RichardCranium]

Bull shit, air flow is air flow.

Here is why you are incorrect

As you can see by the equation in the video, drag increases with velocity squared, so that means it is an exponential growth formula which means that the faster you go, the more drag is created. 200mph has roughly 4 times the drag of 100 mph. 200mph has 16 times the drag of 50mph. So highway speed of 65mph compared to 3 times the speed or 195mph would have 9 times the drag.

 

[Guv]

Who drives 65 anymore?
I wonder how much auto manufacturers spend on wind tunnel testing?
I guess Toyota is just throwing their money away by not just slapping a Prius badge on a Carolla and calling it a day. Incremental gains are all part of the sum, small increases do add up, even at highway speeds professor.

 

[Montana]

No way in hell you gain a 7% in MPG's with a tonneau cover.

That's 2 MPG's more for the average EB driver and 3-4 for the average Hybrid drivers (estimating 28 for EB's and 36-40 for the Hybrids).

No. Way.

Fuelly reports or it's not happening, and since this is not my first truck with a tonneau cover, and I've used Fuelly for years both before and after adding them, I'm calling bullshit. If you are noticing anything, it's not from the tonneau cover. If you had said 1 MPG at most, it might be believable. But 7%? BS.

 

[jewc75]

No way in hell you gain a 7% in MPG's with a tonneau cover.

That's 2 MPG's more for the average EB driver and 3-4 for the average Hybrid drivers (estimating 28 for EB's and 36-40 for the Hybrids).

No. Way.

Fuelly reports or it's not happening, and since this is not my first truck with a tonneau cover, and I've used Fuelly for years both before and after adding them, I'm calling bullshit. If you are noticing anything, it's not from the tonneau cover. If you had said 1 MPG at most, it might be believable. But 7%? BS.

I reported what others said, lol. There are multiple truck forums and independent testers who threw out the 7% number. Its not hard to believe that if you decrease drag your mileage will go up. My awd ecoboost is driven 90% at 80-85 mph and gets 28.1 mpg. When i get a bed cover on im hopeful i will get an increase. If its 1-2 mpg i will call it a win.

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