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Old 07-09-2019, 08:55 PM   #12 (permalink)
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Join Date: Dec 2008
Location: Eugene, OR, USA
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Lord Vader - '15 BMW i3 REx
90 day: 35.06 mpg (US)
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Originally Posted by Vman455 View Post
I would hesitate to go any lower than you have already; generally, there's a "sweet spot" where CD goes down as the body is lowered, but rises again with more lowering. According to the aerodynamics textbooks I've read, this is somewhere around 0.75 body cover:1 wheel diameter.
Agreed. I don't think there is much to be gained there, although I am also looking at adding a front splitter. The front bumper profile rounds under relatively smoothly, but that would reduce some of the pressure and lift I get under the front end at higher speeds - and hopefully clean up aero overall.

Mirrors will be your best bet. That underside looks very good for a production car already, but you may be able to cover the opening at the front subframe and behind the motor at the rear (or is yours a REx?).
It is a REx, so it does need to breathe a bit, but I wonder if just adding an exhaust louver over that rear most opening flat with the rest of the covering would help. Supposedly the REx version has a 0.01 cd penalty, and I can't figure any other place that could be coming from aside from that opening.
2015 BMW i3 REx
2011 Ford Flex SEL AWD
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