Punching a hole in your engine to increase MPG?

[Atheria]

Okay, this sounds drastic, but a few years ago I was talking to this guy who had a standard sedan style Toyota Yaris and swore he got 50+ mpg. He had punched a hole in some part of the engine (wish I could recall where) to let in more air, and although he lost power...he felt the increase in mpg was well worth it. Does this make sense to anyone? I'm leery to make a hole in my engine, but....but.....

Thank you,
Atheria