I have a 1998 3100 Open with twin Crusader 454 XLi engines. They have 900 hours and it tops out at 30 knots. Cruises nicely at 18-20 knots at around 2800-3000 rpm. Full fuel and water, three guys on board. Estimate fuel at around 0.9 MPG. If you want increased range, I would go for diesels. Otherwise I think this setup is fine.
The following 1 user Likes Pknappe's post:1 user Likes Pknappe's post ardoski14 (11-10-2020)