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Old 01-01-2011, 09:56 AM   #1 (permalink)
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Interesting read on pickup truck aerodynamics.

It seems the geometry of a truck bed has a great effect on the Cd of the pickup truck. This research paper presents some interesting wind tunnel data and explains why later model pickup trucks have such high side walls and tailgates.

It seems the manufacturers have sacrificed the utilitarian aspects of earlier model pickups (with low side walls and tailgates) for the taller bed height we see on the late model pickup trucks, especially those trucks with the shorter beds. It's all about reducing the Cd of the pickup truck to improve the fuel efficiency of the truck.

http://www.wseas.us/e-library/confer.../FMA/FMA17.pdf

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Old 01-01-2011, 10:35 AM   #2 (permalink)
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Interesting.
Makes sense though. Same principle of why wagons and stretch limos get better FE.
Apparently flow reattachment over length is more important than I thought it was.
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Old 01-01-2011, 01:27 PM   #3 (permalink)
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Quote:
Originally Posted by JasonG View Post
Interesting.
Makes sense though. Same principle of why wagons and stretch limos get better FE.
Apparently flow reattachment over length is more important than I thought it was.
That would explain why all of those late model pickup trucks have such high beds. They're almost like open-topped versions of the traditional van body.
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Old 01-01-2011, 03:07 PM   #4 (permalink)
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bondo -

Great find! Do you think that this stuff like this could be a missing detail in the "tailgate up/down" theory? That is, it depends on the length of your bed (the geometry!) :



What do you think?

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Old 01-01-2011, 03:09 PM   #5 (permalink)
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yea i guess that makes sense after i think about it
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Old 01-01-2011, 03:18 PM   #6 (permalink)
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Thx Bondo and cfg83.

I thought the high bed walls were for a more massive/macho look.
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Old 01-01-2011, 04:21 PM   #7 (permalink)
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That does not explain why the body is jacked up and why the frontal area of a truck is so big! even the little Toyota trucks are a half ton truck, just like F-150's and Toyota made a 1 ton truck that wasn't much bigger then their half ton truck.
That paper seems to agree with the van shape but the big problem with trucks is that you need a step ladder to get in to the truck bed.
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Old 01-01-2011, 05:43 PM   #8 (permalink)
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Quote:
Originally Posted by cfg83 View Post
bondo -

Great find! Do you think that this stuff like this could be a missing detail in the "tailgate up/down" theory? That is, it depends on the length of your bed (the geometry!) :



What do you think?

CarloSW2
It may very well be. You have now attached a theory to a theory but it does make sense. Your graphic does a very nice job of explaining your thought.

That is definitely thinking oustside of the box!


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Old 01-01-2011, 11:23 PM   #9 (permalink)
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This would militate toward the sloped sidewalls of the GM Avalanche.
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Old 01-02-2011, 06:06 PM   #10 (permalink)
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Quote:
Originally Posted by t vago View Post
That would explain why all of those late model pickup trucks have such high beds. They're almost like open-topped versions of the traditional van body.
I suspect they did not get high for aero; they are high because of the ginormous wheel/tire packages driving the entire chassis up. The cabs are higher too.

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