Thanks all.. Honestly the only thing I want is MPG.. Do not care about the noise, HP or anything else... just more MPG.. The tuner I was trying to avoid because of warranty issues.. so maybe after it runs out I might think about it.

I forgot that it does make the engine louder... that honestly might be an issue as the wifey drives the expy the most and she might not like it...

So really the tuner might be the better option for what I am looking for.