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Do Tonneau Covers Really Save Gas?

Can a tonneau cover save you money on gas?

Are you wondering if adding a tonneau cover to your pickup truck will help your fuel economy and save you money on gas?

It’s a great question! And there are a lot of answers out there. We’ve waded through all the different studies and explanations so you don’t have to. We decided to write an unbiased summary of the main things you’ll find when you look into tonneau covers and gas mileage.

Want to start with more basic information? Read: What is a tonneau cover?

utility truck bed tonneau cover

How much gas does a tonneau cover save? Let’s dive in.

Logically, many people assume that covering the bed of a pickup truck would reduce drag. They think that the open cargo space plus the tailgate capture air flow and lead to more drag at high speeds. In theory, anything to make the truck more aerodynamic and reduce drag would mean better gas mileage. And better MPG would mean money saved at the pump.

It’s no wonder people are so curious about whether tonneau covers improve gas mileage.

There are lots of different ways to approach the problem, and a handful of studies have been conducted to get a good answer. The question was even addressed by the hit TV show “MythBusters”.

There are also a lot of opinions out there. Some are based in science, others not. We’ll stick to the facts and help you evaluate for yourself whether your tonneau cover will really save gas.

The Wind Tunnel Study

In 2007, the Specialty Equipment Market Association (SEMA) conducted one of the most scientific studies on this question. Their team tested four trucks of different makes and 13 different tonneau covers. The trucks tested were:

The 13 tonneau covers included all different materials of soft and hard covers. There were a variety of styles including roll up, retractable, folding and hinged. They decided not to release the data about any specific tonneau brands they used.

They tested the trucks in a full-size wind tunnel. They took their experiment to the AeroDyn Wind Tunnel in Mooresville, North Carolina, which is often used by NASCAR. The tunnel let them test how the trucks performed both with and without tonneau covers.

Their goal was to measure whether the tonneau covers reduced drag.

The wind study tunnel found that each truck had less drag when using a tonneau. The results weren’t huge, but they were measurable. On average, using a tonneau cover led to a 5.7% reduction in drag. That reduced drag meant about a 1.8% increase in fuel efficiency.

Even though 1.8% better gas mileage isn’t massive, it definitely makes a difference over a year of fueling up your truck. The verdict of the Wind Tunnel Study? Using a tonneau cover could give you a modest increase in savings on gas.

The “MythBusters” Study

Did you catch the episode of “MythBusters” where TV’s favorite mad scientists test whether tonneau covers really save gas? In episode 64 in of the series (2006 Season Episode 21 revisited), Adam Savage and Jamie Hyneman make modifications to a truck and test which ones improve fuel economy. They test a few factors:

  • Tailgate down.
  • Mesh tailgate.
  • No tailgate.
  • Hard tonneau cover.

They found that the mesh tailgate noticeably improved the car’s MPG, but none of the other modifications made a difference.

Some people criticize their study for only using one truck. But if you want to go with Adam and Jamie’s perspective, you shouldn’t buy a tonneau if the only thing you care about is saving on gas.

This is the second time MythBusters has addressed this subject. Because of the controversy surrounding this revisited myth, we wouldn’t be surprised if it is in another episode.

Consumer Reports Test

Consumer Reports ran their own small test in 2013 conducted with a Dodge Ram V8. They tested two factors. One was whether having the tailgate up or down made an impact on fuel economy. The other was whether a soft tonneau cover improved fuel economy.

Surprisingly, they found that driving with the tailgate down or with a soft tonneau cover actually made fuel economy worse. But, it’s important to consider that not only did they just use one tonneau cover, but they also only used one truck. 

This study about whether tonneau covers improve gas mileage doesn’t carry much weight, but it still comes up when people discuss tonneau covers and fuel economy.

Other Factors to Consider

These three studies don’t address two big issues:

Driving Speed

One important thing to note is that most of these studies are based on driving trucks at highway speed. Most pickup truck drivers find themselves doing a mix of highway driving and stop-and-start city driving. This means that any impact on fuel economy probably only applies for the time the driver spends traveling at higher speeds.

If you consider the usual mix of driving speeds, saving on gas is even less likely.

Tonneau Cover Weight

Some tonneaus are heavier than others. Heavy tonneau covers, like ones made of fiberglass, may lower gas mileage. Lighter ones, on the other hand, don’t add much weight to the truck and aren’t likely to interfere with gas mileage. 

You’ll have to consider driving speed and tonneau cover weight for yourself when deciding whether to buy a tonneau cover for your pickup truck.

Where do we land? How much gas does a tonneau cover save? 

Thanks for joining us on our tour of the science and madness behind the question: “Do tonneau covers really save on gas?” 

As you’ve seen, there are lots of different angles and opinions to consider. One main study showed a modest increase in fuel economy, while one showed no gain and one showed a potential loss of fuel economy. 

We think the results from the most scientific of these tests, the SEMA study, are encouraging. They showed that using a tonneau cover may add a modest improvement to your gas mileage.

We’ll let you pick which studies are the most reliable and whether you want to invest in a tonneau before the next time you gas up your truck.

So, should I use a tonneau cover?

Of course, improved gas mileage isn’t the only reason to use a tonneau cover on your pickup truck. In fact, it’s not even high on our list. There are lots of other great reasons to get a tonneau cover.

Simply put: tonneau covers help secure and protect your truck bed and cargo. Do you want to leave your cargo out in the open, exposed to the elements? If not, you should consider investing in a tonneau cover. Do you really need another reason?

Plus, there are so many types of tonneau covers on the market. Most pickup drivers can find one best suited to the type of driving they do and the kinds of cargo they carry.

  • Hard tonneau covers provide the strongest protection and can lock to prevent theft.
  • Soft tonneau covers are lighter, more affordable and more flexible, with models that roll, retract and more.

Read more from our blog: “How to choose the best tonneau cover for your pickup truck

Considering buying a tonneau cover? 

Check out the Sawtooth Tonneau Cover. It’s the only tonneau cover that uses patented adjustable truck bed cover material that expands to cover large and tall cargo. Contact one of our tonneau cover experts today!