My 4th hear clutch is gone and Just wanting to ask anyone that has replaced 4th gear clutch in a gtp, its going increase MPG but by how much? The reason why I ask is because I baby mine and drive 80% highway and get anywhere from 18-20 MPG. Now with a 4th gear what should I expect as far as an increase? I know people are going to talk about driving styles and things. I only get on it like once a week. Also I'm very curious to how much you guys are getting out of a full tank of gas. Thanks for any help TJ