I was able to hit just over 100% over EPA rating on my Paseo without any mods besides tire pressure. I was just shy of 60 mpg on my 29 mpg rated Paseo when I started modding it. Now my wife drives it and it gets nowhere near that.
To get that high you absolutely need to use pulse and glide with engine off coasting, and avoid the brakes like a plague. After you've achieved that, the main gain is from reducing your speed.