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Old 04-09-2016, 08:25 PM   #193 (permalink)
bwilson4web
Engineering first
 
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Join Date: Mar 2009
Location: Huntsville, AL
Posts: 843

17 i3-REx - '14 BMW i3-REx
Last 3: 45.67 mpg (US)

Blue Bob's - '19 Tesla Std Rng Plus
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2016 Prius Gen-4

Hi folks,

Sorry to be away for a while . . . been busy. But I wanted to share a validated, mph vs MPG chart for the 2016 Prius:
  • Started with the EPA roll-down coefficients from the "Test Car Database."
  • Got a clarification e-mail from EPA on which coefficients corresponded to different models
  • Used 'mph * (C + (B *mph) + (A * (mph ** 2) ) ) / 375' for drag power.
  • Used 600 W for vehicle built-in overhead based upon previous metrics from Gen-1 and Gen-3
  • Adjusted the curves to reflect 'mph vs MPG' metrics
So this is what the per-model curves look like:


And here is the metric version:


I've also picked up four SAE papers by Toyota that reveal details about 'how they did it.' These became available April 5th so the data is pretty new. Basically, Toyota tweaked everything and the results show.

In our case, we have a 2003 (170k) and 2010 (70k) Prius but the automatic braking won't be available on a Level 2 ECO until 2017. So I'll reduce our inventory to just the 2010 Prius and get the 2017 Level 2 ECO next year. Since I'm patient, I'll use buyer tricks to get exactly what I want for a good price (assuming gas remains cheap!)

Bob Wilson
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2019 Tesla Model 3 Std. Range Plus - 215 mi EV
2017 BMW i3-REx - 106 mi EV, 88 mi mid-grade
Retired engineer, Huntsville, AL
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