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Originally Posted by sad-lumina-owner
Even car aerodynamics has concentrated less on MPG and more on coolant airflow issues, as a close examination shows.
THere is lots more that car makers could do to increase MPG into the 50 mpg range, but they refuse to do so, and have concentrated on increased profits, marketing, and pleasing other big international corporate concerns.
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Decreasing frontal area and streamlining to reduce drag and improve fuel mileage is what
necessitated directed airflow under the front to begin with....sure, we could just make the entire front end closed up. Then it would get an extra 2 mpg, but you could only drive it 3 minutes at highway speed before overheat. Doesn't seem like a logical tradeoff....
No matter what you do, if you're going to use a liquid to air heat transfer system, you have the problem of having a large radiator that needs to be plowing air SOMEWHERE on the car....doesn't matter if you relocate it, break it into smaller units, use electric fans instead of vehicle movement, etc...all that comes with a penalty in additional weight and complexity, cost, power/economy loss from electrical generation, etc...and the net result is nothing is improved and you still have to have the same amount of air drawn from, and exiting into the slipstream...so the most efficient use for all concerns is to utilize some portion of the highest pressure available, and direct it to exit into low pressure areas, creating an enhanced airflow pattern that both does something useful (cooling) and improves undercar aeros...which is exactly what they've done...
You statements are so ridiculous I don't know where to start...cars have been exhaustively tested in wind tunnels, looking for every conceivable reduction in drag...you see it in everything from elimination of rain gutters/channels, flush mount weatherstripping, modular headlights, rearview mirror airflow modeling, wheel opening contouring, wiper design and position when stowed, door handle design, even antenna elimination or design improvements, all the way to airflow modeling that reduces drag inducing turbulence at the rear of the body ...the only reason you have to bleed the cooling system on most modern cars is because the radiator is positioned lower than the highest point in the engine cooling jacket, to accommodate tapering hoodlines and reduce frontal area/height...
all this comes with added benefits besides just fual economy...you also get a quieter car, better visibility (frontal anyway, rear deck/window opening lines are very high now) and the overall shape of the vehicle body enhances stability as speed increases, rather than trying to lift and float like older cars would..there is a slight tendancy towards downforce.
The typical family sedan now carries a drag coefficient very close to that of a .50 cal bullet...one of the most areodynamically perfect forms ever engineered...
Put on your tin foil hat and take your meds, we'll have someone there shortly...