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Old 05-16-2020, 12:27 AM   #8 (permalink)
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Location: Butte, Montana
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little jona - '91 Dodge D 250 first gen cummins LE
Team Streamliner
90 day: 23.4 mpg (US)

Little Jona airo modded - '91 Dodge RAM 3/4 TON D 250 24 AUTO
Team Cummins
90 day: 18.5 mpg (US)

The Salted Hound Jenny. - '87 Dodge Ram 50/D-50 5sp 4X4
90 day: 20.24 mpg (US)

Jona Allison aero - '91 Dodge Ram D-250 Le
90 day: 20.76 mpg (US)
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Originally Posted by Piwoslaw View Post
Originally Posted by guyed
if you look to the left of the cab, you can see the effectivly sheet plastic 1/4 circle vertical deflector.
The only semicircle thing I'm making out to the left of the cab is the spot / convex Mirror On the passenger side. Or are you referring to what the arrows are pointing to on the front beside the grill above the head lights?

Does this help by deflecting towards the rear air that would normally be pushed to the side, thereby gaining forward momentum (sort of like a sail), or is this outweighed by the penalty of extra drag?
Primary purpose in my eye , is the your first part of your question. To divert air to the rear. That would otherwisewould go into making a larger dynamic frontal aera.

That visor has a much smaller outlet than inlet. It takes energy to compress air.
Agreed compressing AKA working cost energy. But with the right geometry the parasitic loss can be reduced for a net gain as dimminstrated
+Cd*-A can be LESS FUEL
Dose the extra work (+Cd) offset the reduced dynamic A(-A)
For a totle reduction of CdA? That depends on how you design it. I'm willing to put money these pictured on this truck reduced the total.
1st gen cummins 91.5 dodge d250 ,HX35W/12/6 QSV
ehxsost manafulld wrap, Aero Tonto
best tank: distance 649gps mi 24.04 mpg 27.011usg
Best mpg : 31.32mpg 100mi 3.193 USG 5/2/20

'83 GMC S-15 Jimmy 2door 2wd O/D auto 3.73R&P
'79 Chevy K20 4X4 350ci 400hp msd custom th400 /np205. 7.5-new 14mpg modded befor modding was a thing
87' Hyundai Excel
83 ranger w/87 2.9 L FI2wd auto 18mpg on the floor
04 Mitsubishi Gallant 2.4L auto 26mpg
06 Subaru Forrester XT(WRX PACKAGE) MT AWD Turbocharged 18 plying dirty best of 26mpg@70mph
95Chevy Blazer 4x4 auto 14-18mpg
04 Chevy Blazer 4x4 auto 16-22mpg

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