Yamaha SWS vs. Direct Injection

[EagleOCNJ]

I have twin 15 Fichts that run good. Hrs are 600 or so but they run good. I have a friend whose boat burned in a boatyard as a result of the boat next to his fully engulfed in flames.

The motors are 2000 Yamaha SWS 150's. The boat was totaled but motors were insured separately so they are his to keep or sell. I can get them at market value but my question is this:

What will be the fuel comsumption difference between my Direct Inject 150s vs. his old style injected engines. Some will say it doesnt matter but it does. I can do all day trolling at the canyon on a nice day for 100-110 gals. If it roughs up I may burn a little more than that.

Does fuel consumption go up 5%,10%, 15%, 20%? While on the topic, what are your thoughts about the diff between carbed, injected, and direct injected economy wise?