Quote:
Originally Posted by Frank Lee
Pic show partial cover giving somewhat less improvement than full cover, yet in one of aerohead's recent posts he lists partial cover as being waaaaay more effective than full cover. I think aerohead suffered a typo...
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I don't have my work book with me so I don't have specific numbers.
GM's patent for the 1/2-tonneau was based on a C-10 pickup before the
'all-new' truck debuted.
In their US Patent they have a performance graph of the cover,as a function of percent coverage of the bed,as measured from the back.
The 1/2-tonneau did have lower drag than the full cover.
Texas Tech based their research on an F-150 short and long bed,both in model and full-scale.And its clear that their data reflect no advantage to the full cover.
When Sport Truck Magazine did a cover story on pickup aero,they had quotes from reps from each of the Big-Three auto/truck makers.From the reading you are led to believe that each pickup must be taken on a case-specific basis.
Consensus was that
'gate-up' was best,although at least one rep reported that if the gate could be hinged at the top,then their truck would show a better number.
It's not gonna be a one-size-fits-all situation.
Short of having access to a wind tunnel I'd be comfortable with going with the gate up,1/2 tonneau combo.
It worked on the pre-T-100 Toyota pickup,1990s Ford 4X4,late 80s Chevy 1/2-ton,T-100,'62 Dodge D-100,1st-gen Tundra.These I know of 1st hand.