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Old 02-08-2022, 02:21 AM   #7 (permalink)
bwilson4web
Engineering first
 
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Join Date: Mar 2009
Location: Huntsville, AL
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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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Quote:
Originally Posted by redpoint5 View Post
Seems like STP (standard temperature and pressure) applies here when making comparisons. Though I have never reviewed EPA testing criteria, I'm sure it would include this, with correction factors for testing outside of STP.
The SAE sells the roll down specifications and procedure for $85. Over time, I've caught snippets and yes, it has fairly extensive Standard Day processes.

About five years ago, I tried to perform my own roll down tests using a recording GPS application and realized it would take more time and effort than I wanted to spend. The GPS altitude metric and delays of low cost GPS were the biggest problem. Combined with high accuracy accelerometer data, it might work.

Quote:
Originally Posted by redpoint5 View Post
I wonder how long until the EPA busts the first overinflated EV efficiency claim?
The folks at "InSideEV.com" consistently claim the Tesla EPA metrics are too optimistic while other EVs vary. But their procedures leave a lot to be desired such as benchmarks at 70 mph with no density altitude corrections.

InSideEV reports the biggest difference is Tesla uses the 5-step procedure of the ICE world and other EV makers use a cheaper 2-step with an EPA mandated 'engineering factor.'

With over a decade of Prius experience, I'm a little persnickety about mileage and range metrics. Consumer Reports still pisses me off. Personally, I prefer the old Edmunds "Smackdown" series.

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

Last edited by bwilson4web; 02-08-2022 at 02:43 AM..
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