My 21' Bayliner with a 5.0L engine got 5MPG and it was carb'd. My 24' wellcraft with a carb'd 7.4L can get 3.0MPG and that is measured with a flow meter. My most economical speed is 35MPH at 3500 RPM with my carb'd 7.4L.
Bottom line...don't go to MPI for the fuel economy. My brother had my same engine with a slightly larger boat with MPI and his MPG was much less.
Bruce. That’s incredible fuel economy for a carb 5.0. What speed was that at ? General cruising ? Those carb 5.0 are pretty efficient. They can’t be compared to the 5.0mpi though. Down on HP.
Good going Bruce. Hull must be really efficient. I thought I was doing well haha.
Think my best set up is 2600rpm according to smart craft. Can’t remember speed at that. Be likely about early to mid 30’s gps. Most comfortable at 2200 and about 25mph odd.
So, thought about it for months. I’m using 5.0 all summer, video record how well it starts, idles and runs. Pulling it in the fall, building a 4 bolt 383 stroker. Selling 5.0 on eVil-bay
