Thank you for your inquiry. The Intrepid 370 cuddy with twin Yamaha 350’s will run as follows, 3500 RPM- 24 GPH- 33 MPH, 4000 RPM- 27 GPH- 35 MPH, 4500 RPM- 34 GPH-40 MPH, WOT 68 GPH- 56 MPH. This does not take into account any enclosure, electronics or bottom pait on the boat. These numbers are based on light load and your results will vary. Please let me know if there is anything more.