As I understand it, the gas crisis of the mid 70’s saw everyone shifting from making/buying cars that were either as big or as powerful as possible and getting sometimes single digit gas mileage to much more fuel efficient vehicles. But while cars got smaller and lighter and engines got handicapped for the sake of efficiency, it seemed that cars of this period were some of the least aerodynamic vehicles since the dawn of automobiles, especially compared to the bubble cars of the 40s and 50s. This seems counter productive.
In: Engineering
As an example of a car that experienced an aerodynamic improvement late in its life (1991->1992, one of the last boxes), Ford Crown Victoria went from a drag coefficient ^[1] 0.42 to 0.34, when moving from the earlier boxy styling to something much more modern.
While this change would make a considerable impact on efficiency at modern highway/tollway speeds (often 75MPH and higher), it would not make anywhere near the same impact if the 55MPH “National Minimum Speed Limit” ^[2] were rigorously enforced, as drag rises exponentially ^[3] with speed.
I suppose, though cannot confirm, that the lack of improvement may have been partially driven by this lack of apparent need.
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^1 [^Drag ^coefficient](https://en.wikipedia.org/wiki/Drag_coefficient) ^- ^basically ^how ^draggy ^something ^is, ^without ^considering ^its ^area ^or ^total ^drag
^2 ^[NMSL](https://en.wikipedia.org/wiki/National_Maximum_Speed_Law) ^law ^enacted ^in ^1973, ^changed ^to ^65MPH ^in ^1987, ^repealed ^1995
^3 ^This ^is ^an ^oversimplification; ^as ^another ^user ^pointed ^out, ^this ^is ^more ^or ^less ^true ^at ^higher ^speeds, ^but ^gets ^more ^complicated ^as ^one ^moves ^slower.
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