Article - Do Tonneau Covers Save MPG?

[RunItHard]

Interesting study. Verifies some of the finding on "Myth Busters". I'll find out for sure after I install the Undercover I just ordered. I've been tracking my MPG since the first day I took delivery of my truck. I'll post my findings after I install the the bed cover, then again after I switch to Mobil-1 0-20 full synthetic.

Ford F150 Tonneau Cover Saves MPG

[Mickey]

Originally Posted by RunItHard

Interesting study. Verifies some of the finding on "Myth Busters". I'll find out for sure after I install the Undercover I just ordered. I've been tracking my MPG since the first day I took delivery of my truck. I'll post my findings after I install the the bed cover, then again after I switch to Mobil-1 0-20 full synthetic.

Ford F150 Tonneau Cover Saves MPG

I don't see or agree with a 3mpg increase on a tonneau cover. I had a Ford snapless tonneau cover which was a joke going down the interstate. It would undo and flap in the wind. They are trying to sell a product.

[TexBiker]

I've run hard tonneau covers on every truck I've owned since the late '80's. None of them had any benefits with regard to fuel economy.

[ramoine]

Read this one

The Tonneau Cover Fuel Economy MYTH | tundraheadquarters.com


OUR BS METER WENT OFF when we read that last line. Is SEMA actually saying that they spent the money to test aerodynamic drag on four different trucks, but that they didn’t spend just a little bit more to find out about actual real-world fuel economy savings? Something doesn’t smell right…

Here’s our interpretation of the study:

1) The largest reduction in aerodynamic drag (7.8%) was observed at 85mph. If we’re generous, we could assume that 75% of the engine’s power is being used to overcome the force of drag at this speed (the other 25% goes to tire friction, heat loss, etc.). If drag is reduced by 8%, that would result in a 6% reduction in engine workload. If the truck averages 18 mpg at this speed, then reducing engine workload 6% would improve fuel economy 1.08 mpg. SO, at 85 mph, expect to see about a 1 mpg improvement with a tonneau cover.

2) At a more realistic highway speed of 65 mph, drag is reduced about 5.5%. Using the same math as above but assuming that only half of the engine’s power is being used to overcome drag at this lower speed, fuel economy is improved by 0.5 mpg.

3) At 55mph or below, the fuel economy benefit basically disappears. Aerodynamic drag isn’t significant until you reach speeds of about 55-60 mph. Technically there would be a fuel savings, but it would be small. Less than a tenth of a mpg.

4) Finally, there were 6 different tonneau covers tested. SEMA didn’t disclose which was which, but we’re fairly certain that a fitted, over the rail solid fiberglass tonneau cover gives the best fuel economy results. The cloth/vinyl covers buffet in the wind, and anything that doesn’t go over the rail creates it’s own vortex. Painted to match, these covers cost $700 to $1100 installed.

Now before anyone goes off on us for making assumptions, etc., we did speak with a couple of engineers when writing this article. They emphasized these are rough numbers, and that they could be off by as much as 25%. That means that the best case fuel economy improvement is 1.35 mpg at 85 mph, and 0.63 mpg at 65 mph.

Assuming gas is $3.50 per gallon, here’s how the best case math works out:

Driving your tonneau cover equipped truck at 65mph for 20 minutes per day would save you 0.04 gallons of gas, or about $0.14 per day. Under these circumstances, we figure it will take about 30 years of workday commuting to save enough to earn back the cost of a $1000 tonneau cover.

Drive your tonneau cover equipped truck at 85mph for 60 minutes a day and you’ll save 0.33 gallons of gas, or about $1.16 per day. We figure that’s only 3 years and 7 months of workday commuting to earn back a $1000 tonneau cover. Of course, during that same period, you’ll spend over $13k on fuel. We feel sorry for anyone that has to drive their truck 85mph for 60 minutes a day — the fuel costs for just three years would be enough to buy a nice toy (ATV, boat, motorcycle, etc.).

Bottomline: Tonneau covers DO save gas, but not very much. While the aerodynamic drag numbers sound impressive (4-8% reduction), they don’t actually result in enough gas savings to justify the expense for a normal user. If you buy a tonneau, do it because it keeps your bed dry and secure.

[Mickey]

Originally Posted by TexBiker

I've run hard tonneau covers on every truck I've owned since the late '80's None of them had any benefits with regard to fuel economy.

Agree with you.

[RunItHard]

Originally Posted by TexBiker

I've run hard tonneau covers on every truck I've owned since the late '80's. None of them had any benefits with regard to fuel economy.

That's exactly what most posts say on most truck forums whether it be Tundra, Ram, F-150, Silverado, etc. It'll be real interesting to see what happens for me in the real world. Not expecting much if anything, but the main reason I'm buying the cover is to keep the elements out of my bed and people from walking off with my stuff. If I pick up a fraction of an MPG it'll be an added bonus.

[Phoenix]

We are looking at hard tonneau covers for our new Tundra (due to arrive at month-end), and our son says that all of the pickups with hard covers that he has seen in parking lots look like the tailgate lock is broken. He says he thinks that thieves probably think that if you have a locking cover, you must have something valuable inside.

Has anyone else noticed this in their area?

Also, I forgot to check at the dealer, does the Tundra tailgate lock closed (with a key)?

[Mickey]

Originally Posted by RunItHard

That's exactly what most posts say on most truck forums whether it be Tundra, Ram, F-150, Silverado, etc. It'll be real interesting to see what happens for me in the real world. Not expecting much if anything, but the main reason I'm buying the cover is to keep the elements out of my bed and people from walking off with my stuff. If I pick up a fraction of an MPG it'll be an added bonus.

I agree with you. I use mine for cover and roll it up when I need it. If I get some kind of mpg the more power to me.

[ramoine]

Yes it locks with a key , the same one as the ignition .

[Mickey]

Originally Posted by Phoenix

We are looking at hard tonneau covers for our new Tundra (due to arrive at month-end), and our son says that all of the pickups with hard covers that he has seen in parking lots look like the tailgate lock is broken. He says he thinks that thieves probably think that if you have a locking cover, you must have something valuable inside.

Has anyone else noticed this in their area?

Also, I forgot to check at the dealer, does the Tundra tailgate lock closed (with a key)?

YES and The hard top is great but I can't remove it by myself when I need the full bed. So a soft top is perfect. Turn key to right locks tailgate. Left unlocks it.

[EVOL ARDNUT]

No Savings In Mpg, At All.
Myth It Is.

[Nukedog]

Mythbusters never tried with a touneau. I can see it would maybe increase 1mpg on a good day but i doubt it is noticeable...

[Mickey]

Originally Posted by Nukedog

Mythbusters never tried with a touneau. I can see it would maybe increase 1mpg on a good day but i doubt it is noticeable...

They did try it with a dodge dakota. They went through hard/soft top tail gate down/up and tail gate off and then an air net. The air net won. It was the only one that showed an increase in gas mileage.

[Impelled]

My ARE lid weighs....a lot, don't know for sure. What "little bit" of mileage I may save due to aerodynamics are probably negated by the weight.

Sell the truck and ride a moped

[Mickey]

Originally Posted by Impelled

My ARE lid weighs....a lot, don't know for sure. What "little bit" of mileage I may save due to aerodynamics are probably negated by the weight.

Sell the truck and ride a moped

But it looks good!!!!