Does removing a truck's tailgate reduce aerodynamic drag?

[Matt Timion]

In short, no. Let this be a place to discuss this for future visitors to the site.

http://web.archive.org/web/20030414234420/mars.acnet.wnec.edu/~ehaffner/Net.htm

Replace Tailgate with a Cargo Net

The picture below shows the flow using a net to replace the tailgate. The characteristics are the same as the "Tailgate removed", however, flow seems to disturbed or mixed as it exits the rear of the bed. The net causes more drag than with no tailgate. The drag coefficient with the net in place is 0.46. This is a 6.71 % increase in drag from the baseline condition.

Please add your links or comments about this old husbands tale.

BTW, WITH the tailgate installed and up the water tunnel looked like this:



In other words, removing the tailgate hurt aerodynamic drag.