Quote:
Originally Posted by bondo
Hello aerohead. I have been running a tonneau cover and this rear cab spoiler device for a few months now. I am getting an interesting fuel efficiency bump at freeway speeds.
What may be going on to lower aerodynamic drag?
Thanks,
Bondo
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Brett,you're 'sculpting' more air!
The extension is just like a box-cavity,capturing locked-vortices off the roof and both sail panels of the cab.
The outer flow is skipping over the vortices,decelerating,and building pressure,such that when it does separate behind the cavity,the vorticity and turbulence over the tonneau is at a higher static pressure; and also,all the flow is cambered down and in which also improves kinetic energy transfer into the 'wake' above the tonneau cover.
John Gilkison made one for the T-100 back in the 90's,and with a half-tonneau we were seeing 9% mpg,just like Texas Tech with their wing/half-tonneau combo.
Another patent?
She's sweet,just like all your top tier creations!
Great going!