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Tail gate up or down for fuel economy

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Old 05-24-2011, 04:42 PM
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Default Tail gate up or down for fuel economy

Do you think there is a difference?

Myth busters said no
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Old 05-24-2011, 04:45 PM
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Makes no difference.

I got so sick and tired from arguing this with some pals of mine, that I finally broke down and did some CFD analysis. Conclusion: It's actually better to keep the tailgate up (although the difference is negligibly small).
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Old 05-24-2011, 05:01 PM
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IMO, keep it up. Bedcovers are not suppose to help any either!
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Old 05-24-2011, 05:05 PM
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The Myth Busters conclusion is that by having the tailgate down you lengthen the bed and have more down force on the rear tires.


That said, I wonder what the difference would be between tonue cover and no cover, and no tailgate vs tailgate up...


Another good one they did was windows down (turbulence) vs A/C. The CPU #'s said there was a big difference (with A/C using more fuel), but raw data showed that the CPU #'s were off. A/C still used more power, but it wasn't by much.
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Old 05-24-2011, 08:39 PM
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The momey saving isn't really worth all the thought that goes into it. I say run tailgate up and A/C on
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Old 05-24-2011, 08:55 PM
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its been proven over and over. Leaving it up creates a low pressure zone in the bed pushind air out and making truck more aerodynamic. Leaving it down creates turbulence low in the bed. watch a cup in the back as you drive. It will slowly move around and then if it gets higher gets sucked out fast. That is the low pressure area in the bed acts like a bubble.
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Old 05-24-2011, 08:57 PM
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and yes running with the Ac on if far more economical than windows down. Air coming in the windows creates drag and high pressure in the cab.
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Old 05-24-2011, 09:01 PM
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Quote:
Originally Posted by wjb21ndtown View Post
Another good one they did was windows down (turbulence) vs A/C. The CPU #'s said there was a big difference (with A/C using more fuel), but raw data showed that the CPU #'s were off. A/C still used more power, but it wasn't by much.
Yeah, the higher engine load with AC on was offset almost as much by the less wind turbulance as with the windows down.

Another test was following a semi at different distances. Tailgating real close showed no fuel savings. ( even if there was a savings, be offset by the rock chip repair )
Seemed the sweet spot was a little less than normal distance.
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Old 05-24-2011, 09:16 PM
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Quote:
Originally Posted by Wet-N-Wild View Post
The momey saving isn't really worth all the thought that goes into it. I say run tailgate up and A/C on
+1
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Old 05-24-2011, 09:40 PM
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Quote:
Originally Posted by Velocity Tom View Post
Do you think there is a difference?

Myth busters said no
and you are worried why
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