[hat_man]

QUOTE=aerohead;271417]These values were published in Texas Tech's SAE Paper# 881874:'Pickup Truck Drag Reduction-Devices That Reduce Drag Without Limiting Truck Utility'
* For short bed pickup,drag min was achieved with a 24-inch wing @ 12-degrees ( a 19" wing @ 11-degrees was almost as low) and 1/2 tonneau cover [ back 1/2 ].
*For a long bed pickup,a 32" wing @ 8-degrees had the drag minimum when combined with the 1/2-tonneau.
*17 % drag reductions were measured.
* An 'aeroshell' provided a 20% drag reduction.[/QUOTE

I have a long bed. But is that 32" from the cab rearward (covering almost half the bed) or 32" from side to side?

I think I have come up with a simple solution for making a half tonneau that I can quickly convert to a full tonneau. It won't be exactly weatherproof but I never really carry anything of value anyhow.