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Old 07-11-2019, 10:32 PM   #28 (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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Not really happy with this data set as there were significant deviations in distance that seemed anomalous. I used a GPS app, but my sense of where I was stopping each time seemed to match up with what it was producing for distance.

I didn't go any lower than 30 psi because the BMW spec is 33f /40r and it was already complaining about 35 /35. Regardless, it seems pretty clear that exceeding the maximum spec of 50 psi for the tires is likely not productive. Much over 45 may or may not be of measurable benefit. Dropping below 40 however seems to have a clear penalty based upon the averages.

Even so, I have decided to keep pressures at 45 / 50 for now as I like the way the car feels there. Lower pressures just feel mushy.
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2015 BMW i3 REx
2011 Ford Flex SEL AWD
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