I am running a 2000 Johnson 150 carbed. I am almost positive it is the same V6 block as the 200, someone correct me if I am wrong. She is pushing an 84 Wellcraft V20, who loaded comes in at about 4200 lbs. With this setup I have been averaging around 2.2-2.5 MPG, the worst I have seen was 2 MPG. Which unless you go with a four stroke or newer DI you won't see too much better.