By the way: the idea of taking a vehicle like the Prius, with an already "better than average" Cd, and modifying it to make it even more aerodynamically efficient isn't unprecedented.
GM did the same thing with its Cd 0.19 Impact/EV1 for a record speed run:
full grille block (the EV1 ultimately had no grille, but some versions of the Impact prototype had stylistic openings, as well as openings for electronics cooling)
Well, the reason I want to improve the Cd of the Prius, besides what I posted on PC, is that Excell, Hobbit et al have found what they call SHM, or Super Highway Mode. With a stock Prius, the car can hold this up to about 50 mph. At these speeds, in SHM, the Prius is getting 60 to 75 mpg demonstrated. With reduction in drag force, maybe SHM can be used at 62 to 64 mph (which is the max engine un-fired, still rotating speed) and is what the dictates of the proletariat on Chicagoland freeways pretty much force as a minimum crusing speed. Besides, I can't Drive 55.
Donee,
I was thinking the same thing about SHM, perhaps being able to extend it by a few MPH by reducing drag. I have done some testing and found that for my Prius, on a fairly level surface, I can maintain SHM up 47 MPH at just over 71.8 MPG with temps in the mid 50's F. Anything above that and the FE drops quickly.
Just to give you some idea on how the low the Cd would have to be to achieve SHM at higher speeds. Assuming that SHM can be maintained up to 47 MPH in my case, I calculate 7.42 HP is required. If I increase the speed and maintain 7.42 HP:
- At 47 MPH, Cd = 0.260
- At 50 MPH, Cd = 0.205
- At 55 MPH, Cd = 0.142
- At 60 MPH, Cd = 0.099
- At 65 MPH, Cd = 0.070
Why this would not be a market success is completely beyond me! I can only hope that some visionary wannabe at Toyota will rip-off the entire concept,ram it into mass production,and flood the streets with them.A non-hybrid version could be co-produced for sale to the feint-of -heart,not quite ready for all the technical sophistication of the hybrid.The highway performance would still be there,and it would certainly get people talking at the fuel pump.I'm afraid that automotive-related knowledge will continue to spread from the bottom up.This would be a terrific vehicle to deliver the message! It's a beautiful car,thanks for putting that image together,and bottoms up!,Phil.
Hi BestMapMan. I write for Edmunds (http://blogs.edmunds.com/GreenCarAdvisor/). I'm working on an article about ecomodders and would like to communicate with the person who crafted that awesome red machine. Please, where did you come across it?
.14 is really pushing it. Just the basic shape with wheels might make it to .14, but even that is optimistic. As soon as you start to add the windows recesses, joints, wheel wells, muffler, radiator, etc. that .14 is far gone.
Hi BestMapMan. I write for Edmunds (http://blogs.edmunds.com/GreenCarAdvisor/). I'm working on an article about ecomodders and would like to communicate with the person who crafted that awesome red machine. Please, where did you come across it?
That awesome red machine doesn't exist yet except in bestmapman's imagination. It's a photoshopped image of what he wants his Prius to end up looking like. It'll be amazing to see once it becomes reality.
