Quote:
Originally Posted by Cd
I keep seeing this comment over and over.
I remember a comment that Darin made about how important that aero is even at 45 MPH.
Can someone suggest a direct link to some info on this ?
It gets frustrating.
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* There may have been a specific case in which the comment had merit. Perhaps a Bonneville streamliner class vehicle, or the 1993 EV1 land speed record car at Ft. Stockton, Texas. Without the context, we'd be at a loss.
* We know that aerodynamic drag varies as the square of the velocity.
* And we know that the power to overcome aerodynamic drag varies as the cube of the velocity.
* Here's an aero power profile for the 2019 Chevy BOLT ( using Cd 0.31 )
35- mph = 2.3316-hp
45- mph = 4.9557-hp
55- mph = 9.048- hp
60- mph = 11.7468-hp
65- mph = 14.9351-hp
75- mph = 22.943- hp
85- mph = 33.3983- hp
95- mph = 46.6271- hp ( 1-mph over rated top speed )
* One thought, which could explain the comment, might have had to do with the 'cross-over point' velocity, at which aerodynamic drag just began to exceed that of the rolling resistance on a road load power curve for this particular vehicle. For this to be true for the BOLT would require Cd 0.142.
Honk if you have a small one!