Background
There is a lot of opinion out there regarding the efficiency delta between wankel rotary engines and four stroke engines of various configurations (forced induction, etc).
This delta, whatever it is, seems to be a debate of how much. How much waste, how much efficiency, how much power.
What are the actual deficiencies of a rotary engine?
What is the delta of efficiency between a rotary engine and modern four-stroke engine?
What is the root cause regarding the configuration of a rotary engine that makes it so wasteful?