[cosmick]

Originally Posted by Vman455

How so? The Prius, and the scads of other cars that use late-valve-closing, simulated-Atkinson cycle, are not actually Atkinson cycle engines (four strokes in one crankshaft revolution) or Miller cycle engines (which use a supercharger), and function on exactly the same principle as the Hot Rod article engine you're searching for. Someone above asked why this technology didn't "go anywhere"--the answer is, it did. It is even used in high-performance cars today.

Also, the 1NZ-FXE was a clean-sheet design in the mid-90s, and efficient enough that Toyota still uses it in the current Prius C.

Today's most efficient new engine has neither of those.