Those types of generalizations can be so inaccurate that in many cases they are wildly wrong. As said by many previous posters such a chart can be useless. The rules of thumb of just ten years ago really have no bering on a lot of what is out there now.

The performance distinctions between the two types of operating cycle are disappearing. There is at least one line of four strokes out there that arguably in the various displacement catagorys offer more useful power than many of the similar displacement two strokes.

John