Fuel Economy MPI vs 2 stroke outboard

I am running a 99 Wellcraft 20ft Excalibur bowrider with a 5.7L 4bbl Mercruiser. Fuel here (as in most places has sky rocketed - ?7.39 / $9.79 per gallon).

I am looking at trying to find something a bit more economical and am exploring 2 routes:

Option 1, re-power the boat with an MPI
Option 2, buy a smaller boat with an outboard.

I love my Wellcraft and struggled to find something that I could replace it with, I have come across a 2010 Campion Chase 580OB fitted with a 250HP HPDI Yamaha 2-stroke outboard. The boat is 19ft long and almost half the weight (2020 vs 3500), should be better on fuel, Right?

The Campion should deliver in all the same areas as my Wellcraft with regard to performance, but will it be more fuel efficient? (also will it ride as well as the Wellcraft?)

The cost to change the engine to a 377MAG or change the boat for the Campion is almost identical.

Where is my money better spent?

Re: Fuel Economy MPI vs 2 stroke outboard

I have a 115hp 2-stroke Mariner outboard on our 32' Party Cruiser 'toon. I'm astounded at it's crappy gas mileage. And after reading the logs and other notes of the original owner, he probably was too. The average gas mileage as logged by the PO was 1.2 mpg. Our 53' SkipperLiner with twin 120 Mercruiser's easily doubles that mileage...

My other frame of reference, the twin 250hp salt water 2-stroke outboards on a friends 42' pontoon/flat deck aluminum salvage boat (read: very lightweight), he goes thru 48 gallons an hour at 35-40 mph...

My worst gas mileage from a "normal" boat was my old '73 Reinell 24' cabin cruiser, running a pair of 318 Chryslers, I burned thru 63 gallons of gas during the 90-odd miles from Wahweap to Bullfrog on Powell in the summer of '83, running almost exactly 3100 rpm/32 mph the entire trip. Not bad for pair of V8's--

Guess my answer!

Re: Fuel Economy MPI vs 2 stroke outboard

You will NEVER make up any $$$ in repowering for better MPG's. Doesn't happen. It takes a certain amount of hp to move a hull at a certain speed, so to gain MPG's you either have to make it lighter, or reduce the amount of hull in the water. (both of which mean finding a different boat) Yes, MPI will be slightly better, but not enough to ever make the upgrade worth it financially.