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Originally Posted by NHB
Aerodynamic balance is real but so is cooling. When a car has about 1 MW engine power and 400 km/h top speed, it has to be able to dissipate huge amount of heat in various places. For that a supercar needs a lot air running thru cooling system. It's easy to see the effect of power. Let's check Cd-values of Mercedes CLA - one of the most aerodynamic cars available.
0,22 CLA 180 BlueEFFICIENCY Edition 90 kW (skinny tires)
0,25 CLA 180 90 kW
0,29 CLA 250 4MATIC 155 kW
0,32 CLA 45 AMG 4MATIC 265 kW
How high would the coefficient factor be if that chassis had 1 MW engine? I bet it would more that 0,4. Cooling for engine, cooling for transmission, cooling of brakes and huge tires increase drag a lot. A supercar has to be also very wide and relatively short which doesn't help.
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Were those numbers reached with by placing the different engines in the same vehicle? Did each vehicle have the same trim level and body styling package? The answer is probably no.
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0,22 CLA 180 BlueEFFICIENCY Edition 90 kW (skinny tires)
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skinny tires, low A-pillar shoulder with adapted A-pillar geometry, aerodynamically optimized exterior mirror housings and rear shape, optimized diffuser, optimized underbody and rear axle paneling, radiator shutter, aero wheel trims and serrated wheel spoilers on the front and rear wheel arches.
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0,32 CLA 45 AMG 4MATIC 265 kW
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Different rear diffuser, rear fascia with side air outlet openings, Large side cooling intakes with flics (functional winglets), front splitter, different air dam height, different wheels, different suspension components, different exhaust, wider/larger tires, different underbody due to AWD system (underbody is an assumption, I can't find pics).
Details on the cars taken from Wiki and the MB website.
In regards to aerodynamics, these cars aren't the "same" vehicle... To display a difference in CD and say it's due to cooling, would seem to be over simplifying to me.
~C