But then again remember that the current compressors are reciprocating devices. The old saying that much of the power developed by a reciprocating engine goes toward its own self-destruction. Every lenghty deiscussion on marine diesel engines (after the second six-pack) brings this old saw out from one of the participants at some point.
Some, percentage of existing compressors are still reciprocal. But the good old recip, which is still best in some apps, has been in general phase-out since the late 70's, Cap. Nary a new one left on the automotive scene, for example.
Ya got your vane types, your scroll types, and your screw types (helical).
And I remember the 150 MPG carburetor that was bought up by the oil companies/auto companies/government to keep gasoline prices high.