I don't know about that, but it will surely make your car run better. Probably add a little performance, but not by adding hp. It's just like cleaning your air filter once in a while, you'll get better gas mileage (noticeable if you haven't cleaned it in like a year).
in grand tourismo if you got your oil changed before driving it, you would get an extra 50 horse power or something like that. I wouldnt suggest you do that with a real car though. The oil in the car when it is brand new is ment to break in the engine and should be changed anywhere from 3-5 thousand miles