Do you remember that trend from back in the day wherein owners removed the tailgates from their pickup trucks? While some just left it open, a few put a safety net in its place. I can’t vouch for any of them, but I’m sure the reasoning behind it was to let the air flow through the net, thus aiding aerodynamics. In return, you’d get better fuel economy and better performance. If you wondered the same, I’m sorry to burst your bubble because that’s not the case. In fact, it would have adverse effects on your performance and economy.

Why Would Someone Remove The Tailgate?

Well, apparently to improve the fuel economy. There was a notion that the tailgate would act as a barrier and not let the air pass in a thorough motion. This would create drag, thus requiring more power to move forward resulting in higher fuel consumption. At the onset, it might not sound very stupid. But, the logic is flawed when you’re at high speeds because the dropped tailgate creates significantly higher drag.

What’s The Science Behind A Tailgate’s Aerodynamics?

XLPLRCreate conducted a study on a 2014 Ford F-150 and found out that the drag force is 19-percent higher at highway speeds when the tailgate is removed. In this example, it led to a drop of three miles every gallon!

Let me try to explain the logic without getting too technical. When you don’t have the tailgate, the air flows down aggressively from the roof. It creates a strong resistance. From the roof, the air goes down roughly half the length of the bed and then gets sucked into the low-pressure zone behind the cab.

But, when the tailgate is closed, the airflow over the bed is actually smooth. That’s because the air trapped in the bed is circulating behind the cab and has no space to escape. This forces the air to flow from the roof over this circulating air and past the top of the tailgate.

Will A Tonneau Cover Help Save Gas?

The answer is yes. Unless you got on the trend just to seem cool, installing a Tonneau cover will help reduce fuel consumption. There are a ton of studies out there, including an episode of the Mythbusters that talks about this. But, we’re going to stick to the Wind Tunnel Study conducted by SEMA. The study was conducted on four trucks and 13 different types of Tonneau covers. These were the Ford F-150, Chevy Silverado, Dodge Ram 1500, and the GMC Sierra.

The ultimate goal was to test if the covers reduce any drag, and as it turns out, it does. On average, it led to a 5.7-percent reduction in drag. This resulted in about a 1.8-percent increase in fuel efficiency. It doesn’t seem to be a lot, but you can calculate the yearly savings you’ll have. But, another thing that must be noted is that the study didn’t take into consideration the weight of the cover. Mind you, this is the average of the 13 different types of hard and soft covers, which include, roll up, retractable, folding, and hinged. The driving speed will also skew the results largely.

Conclusion

If having no tailgate or a mesh gate in place of a conventional tailgate would improve the fuel economy, I’m sure the automakers would just drop it instead of spending their financial and technical resources in trying to extract maximum miles for every gallon of fuel consumed. It would be the easiest way, wouldn’t it? But, they don’t, so there must be a good reason for it.

Have you ever believed in this logic or know someone who advised you to drop the tailgate to improve fuel economy? Let us know your thoughts in the comments section below.