One of the reasons that you might be looking for a tonneau cover is the claim that tonneau covers save gas. So I know you are wondering,”Is it really true?”
SEMA, Specialty Equipment Market Association uses a study of drag that was made in 1997 by Todd J. Ortolani and Vanwijak Ewosakul at Western New England College’s Department of Mechanical Engineering titled “Improving Aerodynamic Characteristics of a Dodge Ram Pickup Truck.” Basically they discovered that Cd (coefficient of drag) was reduced by 11.81% when compared to a standard model(without mirrors and tailgate up). It shows that the MPG went from 16 MPG for the standard vehicle to 17.18 MPG with a tonneau cover. It may not seem like a large number, but over time this will make a huge difference in your wallet.
Mythbuster’s First Study
You would think that SEMA study would prove that tonneau covers save gas, but there was also a study made by Mythbusters to disprove this logic. Mythbusters is a science entertainment TV program hosted by Adam Savage and Jamie Hyneman. In episode 43, they experimented with the tailgate up vs. tailgate down to see which one was more fuel-efficient. They filled up two exact models of trucks and drove up to 55 mph until they ran out of gas. In the end, it was determined that tailgate up was more fuel-efficient because there was a “locked vortex flow” that was made in the bed of the truck that kept faster air from contacting the truck which reduced drag. This episode recieved so much backlash that they revisited this “myth” in episode 64 which is shown below.
Mythbuster’s Second Study
In episode 64, they experimented with a hard tonneau cover, tailgate mesh, and the tailgate removed. It was determined that the hardcover used up the same amount of gas at 55 mph as the tailgate up, and that the tailgate mesh got the most efficient gas mileage using an electronic flowmeter that was hooked to the fuel line. So it would seem to be the case that the myth of using a tonneau cover saves gas mileage was busted. More recent studies have shown that their tests are not valid.
What we Learned
Their first problem was that the experiment did not include different types of tonneau covers. There are other covers that are lighter than the tonneau cover they used. Problem #2 is that they also only tested at 25 and 55 mph, so it would not include how to drag would be reduced at higher speeds or city driving style. If you do a lot of highway driving and use a lighter tonneau cover, it could increase your gas mileage. A soft tonneau cover could pay for itself in no time.
To conclude the argument, some sites say a tonneau cover will save you 10-15% on gas. According to the aforementioned studies, a cover will actually save you closer to 6% based on what type of cover and how you drive. It may be less than expected, but a cover will easily pay for itself over time – especially with rising gas prices. Use the savings calculator below to see how quick your tonneau cover will pay for itself!
We hope this answered your questions about gas savings with a tonneau cover. We are more than willing to answer any of your tonneau cover questions and assist you in picking the right tonneau cover for your truck.
Actual results will vary – this is an estimated savings based on an annual 6% MPG increase.