' Honey, I shrunk the Lucid Air '.
 

ROAD & TRACK road-tested the Lucid Air, at a constant 65-mph, on I-580, in California, something real motorists might do.
On the 113-kWh pack, they saw 484-miles range.
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With back-of-the-envelope calculations I played 'what if we lowered the Lucid down to Hucho's Cd 0.09?'
* Dropping from Cd 0.21 to 0.09 is a 57 % drag reduction.
* Using the old/new delta -Cd vs delta -mpg relationship @ 65 mph produces a 31.4% mpg-e improvement, increasing range to 636-miles. ( 190-mpg-e vs 144.7-mpg-e )
* 177.6 Watts / mile.
* 9.78- hours drive time / charge.
* 152 extra miles range.
* Equivalent to adding a phantom 35.4 kWhs.
* No appreciable weight gain.
* Elucidation hallucination.:rolleyes:

Is there a fellow here on EM that has a Prius with a boat tail he calls " champrius " ?
I found him on instagram.

He has added a full boat tail / bellypan / gap fillers / grille block / smaller mirrors etc.

He has posted pictures that show he has got 60+ mpg .
I believe this is purely with the aeromods, but I'm not sure that is even possible.

Since the car has a published Cd of .26, what is the new Cd of the car ?

Stock, the car was getting around 45 - 48 mpg.

60+ mpg Prius
 

We'd need:
* year model
* test conditions
* pre-test warmup
* testing methodology, instrumentation, data capture
* no 'hypermiling'
* O.E.M. mpg baseline only from that methodology
* modified mpg of modified Prius, captured during identical methodology, with results normalized to standard SAE air density
* large enough 'sampling' to be statistically significant
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The modified shape can be the only variable allowed. Nothing else about the Prius can be changed unless it's independent effects can be parsed out and quantified. Not even tire pressure. Identical weight.
Technically, all testing should take place on the exact same course. Round trip. Or the sample of sufficient magnitude that it represents a sample as large as that used to establish the OEM baseline. The larger the database, the less background noise during comparisons.
Meteorological data must be accounted for.
Road conditions.

Ok. Nevermind.
Let's just give a hypothetical example.
All things being equal except aeromods, what would the cars Cd be if the car started out with a .26 Cd and 46 mpg
Ending with a Cd of (blank) and 60 mpg.

what would the cars Cd be
 

We need a test velocity, as the relationship is variable with respect to speed.:)
( Aerodynamic power is varying as a function of the cube of the velocity, while rolling-resistance is following a linear 'curve,' up to standing-wave velocity )

Prius @ 60 mpg @ 65 mph = Cd 0.116
 

If say, the original, OEM, 46-mpg was obtained at 65-mph, in order to get 60-mpg ( all other things equal ) would require Cd 0.116.
It's doable.

Are you thinking of this car?

That's the one !

I am the one you've been looking for :)
 

Howdy!

I'm the creator and owner of Champrius. The car got 46 mpg in 2009, but in 2018 (when I bought it), it was down to a mere 39 mpg. After a tune-up and some mechanical love, I was able to get it to 41 mpg as a baseline.

Then I started my aeromod odyssey, which brought the car up to 66 mpg at peak. I use the car to go on extended camping trips, so when she's fully laden in the real world she got 61 mpg. Then a series of tragedies befell her (engine, cat, etc.) and the mpg dropped to a mere 55. :(

Oh, all those numbers are at cruise control @65mph, which is 75%+ of my driving. Real world numbers, and not benchmarked. So we\'re looking at +50% increase in fuel economy through aeromods.

Last but not least, I believe the other fellow on this thread made a major calculation error. There\'s no way in hell Champrius has a 0.116 Cd. The fricking Aptera has a 0.13 Cd. My best guesstimate is that she had a 0.21 Cd, and my goal for the next version Champrius 4.0 is to hit 70 mpg or near 0.185 Cd.

How many campers does it accomodate?

He can be cranky, but we love him. I just realized BamZipPow\'s [ Does anyone know this car] last post was in 2020.