atkinson cycle, five stroke, six stroke

Hi, I have some questions about engines:
Will we have atkinson cycle, five stroke and/or six stroke engines?
I know they will not be in the game at the release, but maybe in the future? Atkinson cycle was invented in 1880's, and some modern cars, like the Prius, use it. And five/six stroke engines are, in theory, more efficient than four stroke, so some people say they are the future.
Will we have atkinson cycle, five stroke and/or six stroke engines?
I know they will not be in the game at the release, but maybe in the future? Atkinson cycle was invented in 1880's, and some modern cars, like the Prius, use it. And five/six stroke engines are, in theory, more efficient than four stroke, so some people say they are the future.